1
FEATURES
DESCRIPTION
ADS62C17
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Dual Channel 11 Bit, 200 MSPS ADC With SNRBoost
Programmable Gain up to 6dB for SNR/SFDRTrade-offMaximum Sample Rate: 200 MSPS
DC Offset Correction11-bit Resolution with No Missing Codes
Gain Tuning Capability in Fine Steps (0.00190 dBc SFDR at Fin = 10 MHz
dB) Allows Channel-to-channel Gain Matching79.8 dBFS SNR at 125 MHz IF, 20 MHz BW
Supports Input Clock Amplitude Down to 400using TI proprietary SNRBoost technology
mV p-p DifferentialTotal Power 1.1 W at 200 MSPS
Internal and External Reference Support90 dB Cross-talk
64-QFN Package (9 mm × 9 mm)Double Data Rate (DDR) LVDS and ParallelCMOS Output Options
ADS62C17 is a dual channel 11-bit, 200 MSPS A/D converter that combines high dynamic performance and lowpower consumption in a compact 64 QFN package. This makes it well-suited for multi-carrier, wide band-widthcommunications applications.
ADS62C17 uses TI-proprietary SNRBoost technology that can be used to overcome SNR limitation due toquantization noise for bandwidths less than Nyquist (Fs/2). It includes several useful and commonly used digitalfunctions such as ADC offset correction, gain (0 to 6 dB in steps of 0.5 dB) and gain tuning (in fine steps of 0.001dB).
The gain option can be used to improve SFDR performance at lower full-scale input ranges. Using the gaintuning capability, each channel s gain can be set independently to improve channel-to-channel gain matching.The device also includes a dc offset correction loop that can be used to cancel the ADC offset.
Both DDR LVDS (Double Data Rate) and parallel CMOS digital output interfaces are available. It includesinternal references while the traditional reference pins and associated decoupling capacitors have beeneliminated. Nevertheless, the device can also be driven with an external reference.
The device is specified over the industrial temperature range ( 40 ° C to 85 ° C).
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of TexasInstruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Copyright © 2009, Texas Instruments IncorporatedProducts conform to specifications per the terms of the TexasInstruments standard warranty. Production processing does notnecessarily include testing of all parameters.
CONTROL
INTERFACE
INA_P
INA_M
CLKP
CLKM
VCM
SCLK
SEN
SDATA
AVDD
AGND
DRVDD
DRGND
14 bit
ADC
INB_P
INB_M
RESET
CTRL1
CTRL2
CTRL3
CLKOUTP/M
LVDS
INTERFACE
ADS62C17
DA0P/M
DA2P/M
DA4P/M
DA6P/M
DA8P/M
DA10P/M
DB0P/M
DB2P/M
DB4P/M
DB6P/M
DB8P/M
DB10P/M
14 bit
ADC
Digital
Processing
Block
Channel A
SNRBoost
Digital
Processing
Block
Channel B
11 bit
11 bit
SDOUT
DDR
Serializer
DDR
Serializer
OUTPUT
CLOCK
BUFFER
SNRBoost
Sample
&
Hold
CLOCKGEN
REFERENCE
Sample
&
Hold
ADS62C17
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These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foamduring storage or handling to prevent electrostatic damage to the MOS gates.
Figure 1. ADS62C17 Block Diagram
PACKAGE/ORDERING INFORMATION
TRANSPORTPACKAGE- PACKAGE SPECIFIEDPRODUCT PACKAGE MARKING ORDERING NUMBER MEDIA,LEAD DESIGNATOR TEMPERATURE RANGE
QUANTITY
ADS62C17IRGCRADS62C17 QFN-64 RGC 40 ° C to 85 ° C AZ62C17 Tape and ReelADS62C17IRGCT
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THERMAL CHARACTERISTICS
(1)
ABSOLUTE MAXIMUM RATINGS
(1)
ADS62C17
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over operating free-air temperature range (unless otherwise noted)
PARAMETER TEST CONDITIONS TYP UNIT
R
θJA
(2)
Soldered thermal pad, no airflow 22Soldered thermal pad, 200 LFM 15 ° C/WR
θJT
(3)
Bottom of package (thermal pad) 0.57
(1) With a JEDEC standard high K board and 5x5 via array. See Exposed Pad in the Application Information.(2) R
θJA
is the thermal resistance from the junction to ambient.(3) R
θJT
is the thermal resistance from the junction to the thermal pads.
VALUE UNIT
Supply voltage range AVDD -0.3 to 3.9
VSupply voltage range DRVDD 0.3 to 2.2Voltage between AGND and DRGND 0.3 to 0.3Voltage between AVDD to DRVDD (when AVDD leads DRVDD) 0 to 3.3 VVoltage between DRVDD to AVDD (when DRVDD leads AVDD) 1.5 to 1.8Voltage applied to external pin, VCM (in external refersnce mode) 0.3 to 2.0 0.3V to minimumVoltage applied to analog input pins INP_A, INM_A, INP_B, INM_B
V(3.6, AVDD + 0.3V)Voltage applied to input pins CLKP, CLKM
(2)
, RESET, SCLK, SDATA, SEN, CTRL1,
0.3V to ADD + 0.3VCTRL2, CTRL3T
A
Operating free-air temperature range 40 to 85 ° CT
J
Operating junction temperature range 125 ° CT
stg
Storage temperature range 54 to 150 ° CESD, human body model 2 kV
(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratingsonly and functional operation of the device at these or any other conditions beyond those indicated under recommended operatingconditions is not implied. Exposure to absolute maximum rated conditions for extended periods may affect device reliability.(2) When AVDD is turned off, it is recommended to switch off the input clock (or ensure the voltage on CLKP, CLKM is < |0.3V|. Thisprevents the ESD protection diodes at the clock input pins from turning on.
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RECOMMENDED OPERATING CONDITIONS
(1)
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MIN TYP MAX UNIT
SUPPLIES
AVDD Analog supply voltage 3.15 3.3 3.8 VDRVDD Digital supply voltage 1.7 1.8 1.9 V
ANALOG INPUTS
Differential input voltage range 2 V
PP
Input common-mode voltage 1.5 ± 0.1 VVoltage applied on CM in external reference mode 1.5 ± 0.05 VMaximum analog input frequency with 2V pp input amplitude
(1)
500 MHzMaximum analog input frequency with 1V pp input amplitude
(1)
800 MHz
CLOCK INPUT
Input clock sample rate 1 200 MSPSInput Clock amplitude differential (V
CLKP
V
CLKM
)
Sine wave, ac-coupled 0.2 3.0 V
PP
LVPECL, ac-coupled 1.6 V
PP
LVDS, ac-coupled 0.7 V
PP
LVCMOS, single-ended, ac-coupled 3.3 VInput clock duty cycle 40% 50% 60%
DIGITAL OUTPUTS
C
L
Maximum external load capacitance from each output pin to DRGND 5 pFR
L
Differential external load resistance between the LVDS output (LVDS interface) 100
T
A
Operating free-air temperature 40 85 ° C
(1) See Theory of Operation in the application section.
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ELECTRICAL CHARACTERISTICS
(1)
ADS62C17
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Typical values are at 25 ° C, AVDD = 3.3V, DRVDD = 1.8V, sampling frequency = 200 MSPS, 50% clock duty cycle, 1dBFSdifferential analog input, internal reference mode, LVDS and CMOS interfaces unless otherwise noted.Min and max values are across the full temperature range T
MIN
= 40 ° C to T
MAX
= 85 ° C, AVDD = 3.3V, DRVDD = 1.8V
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Resolution 11 bits
ANALOG INPUTS
Differential input voltage range 2.0 V
PP
Differential input resistance (at dc) See Figure 44 > 1 M
Differential input capacitance See Figure 45 3.5 pFAnalog input bandwidth 700 MHzAnalog input common mode current (per channel) 3.6 µA/MSPSVCM common mode voltage output 1.5 VVCM output current capability ± 4 mA
POWER SUPPLY
IAVDD Analog supply current 262 mAIDRVDD Output buffer supply current LVDS interface With 100 external 120 mAterminationIDRVDD Output buffer supply current CMOS interface No external load 87 mAcapacitanceAnalog power 865 1025 mWDigital power LVDS interface 216 306 mWGlobal power down 45 75 mWNo missing codes Assured
DC ACCURACY
DNL Differential Non-Linearity Fin = 170 MHz -0.6 ± 0.2 0.6 LSBINL Integral Non-Linearity Fin = 170 MHz -2.5 ± 0.75 2.5 LSBOffset Error -20 ± 2 20 mVOffset error temperature coefficient 0.02 mV/COffset error variation with supply 0.5 mV/VThere are two sources of gain error internal reference inaccuracy and channel gain errorGain error due to internal reference inaccuracy alone -1 ± 0.2 1 % FSGain error of channel alone
(2)
-1 +0.2 1 % FSChannel gain error temperature coefficient 0.002 Δ%/ ° CDifference in gain errorsbetween two channels -2 2within the same deviceGain matching
(3)
% FSDifference in gain errorsbetween two channels -4 4across two devices
(1) In CMOS interface, the DRVDD current scales with the sampling frequency and the load capacitance on output pins.(2) This is specified by design and characterization; it is not tested in production.(3) For two channels within the same device, only the channel gain error matters, as the reference is common for both channels.
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ELECTRICAL CHARACTERISTICS
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Typical values are at 25 ° C, AVDD = 3.3V, DRVDD = 1.8V, sampling frequency = 200 MSPS, 50% clock duty cycle, 1dBFSdifferential analog input, internal reference mode, SNRBoost disabled, LVDS and CMOS interfaces unless otherwise noted.Min and max values are across the full temperature range T
MIN
= 40 ° C to T
MAX
= 85 ° C, AVDD = 3.3V, DRVDD = 1.8V
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SNR Fin = 20 MHz 67Signal to noise ratio
Fin = 70 MHz 66.8
dBFSLVDS
Fin = 170 MHz 0 dB gain 64.5 66.36 dB gain 64.4
Table 1. SNR Enhancement With SNRBoost Enabled
SNRBoost bath-tub centered at Fsx0.25, 1 dBFS input applied at Fin = 125MHz, Sampling frequency = 200MSPS
SNR Within Specified bandwidth, dBFS
Bandwidth, MHz In Default Mode ( SNRBoost Disabled) With SNRBoost Enabled
(1)
MIN TYP MAX MIN TYP MAX
5 78.8 79.6 83 85.610 75.8 76.6 80 82.615 74 74.9 78.2 80.920 72.7 73.6 77 79.630 71 71.9 74.4 76.440 69.8 70.6 72.7 74.5
(1) Using recommended SNRBoost coefficients. See note on SNRBoost in application section.
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ELECTRICAL CHARACTERISTICS
ADS62C17
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Typical values are at 25 ° C, AVDD = 3.3V, DRVDD = 1.8V, sampling frequency = 200 MSPS, 50% clock duty cycle, 1dBFSdifferential analog input, internal reference mode, SNRBoost disabled, 0dB gain, LVDS and CMOS interfaces unlessotherwise noted.Min and max values are across the full temperature range T
MIN
= 40 ° C to T
MAX
= 85 ° C, AVDD = 3.3V, DRVDD = 1.8V
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Fin= 20 MHz 66.9Fin = 70 MHz 66.6SINAD
dBFSSignal to Noise and Distortion Ratio
0 dB gain 63.5 65.7Fin = 170 MHz
6 dB gain 64.2Fin= 20 MHz 85Fin = 70 MHz 83SFDR
dBcSpurious Free Dynamic Range
0 dB gain 73 78Fin = 170 MHz
6 dB gain 81Fin= 20 MHz 83Fin = 70 MHz 81THD
dBcTotal Harmonic Distortion
0 dB gain 71.5 75.5Fin = 170 MHz
6 dB gain 79Fin= 20 MHz 94Fin = 70 MHz 90HD2
dBcSecond Harmonic Distortion
0 dB gain 73 83Fin = 170 MHz
6 dB gain 92Fin= 20 MHz 85Fin = 70 MHz 83HD3
dBcThird Harmonic Distortion
0 dB gain 73 78Fin = 170 MHz
6 dB gain 81Fin= 20 MHz 94Worst Spur
Fin = 70 MHz 92 dBcOther than second, third harmonics
Fin = 170 MHz 80 90
IMD
F1 = 185 MHz, F2 = 190 MHz, Each tone at 7 dBFS 87 dBFS2-Tone Inter-modulation Distortion
Recovery to within 1% (of final value) for 6-dB overload with 1 clockInput Overload recovery
sine wave input at Fclk/4 cyclesCross-talk Up to 200 MHz cross-talk frequency 90 dB
PSRR
For 100 mV pp signal on AVDD supply 25 dBAC Power Supply Rejection Ratio
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DIGITAL CHARACTERISTICS ADS62C17
GNDGND
Logic0
V =-350mV*
ODL
Logic1
V =+350mV*
ODH
VOCM
DAnP /DBnP
DAnM/DBnM
*Withexternal100 terminationW
ADS62C17
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The DC specifications refer to the condition where the digital outputs are not switching, but are permanently at a valid logiclevel 0 or 1. AVDD = 3.3V, DRVDD = 1.8V
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
DIGITAL INPUTS CTRL1, CTRL2, CTRL3, RESET, SCLK, SDATA, SEN
(1)
High-level input voltage 1.3All digital inputs support 1.8 V and 3.3 V CMOS
Vlogic levels.Low-level input voltage 0.4SDATA, SCLK
(2)
V
HIGH
= 3.3 V 16High-level input current µASEN
(3)
V
HIGH
= 3.3 V 10SDATA, SCLK V
LOW
= 0 V 0Low-level input current µASEN V
LOW
= 0 V 20Input capacitance 4 pF
DIGITAL OUTPUTS CMOS INTERFACE (DA0-DA10, DB0-DB10, CLKOUT, SDOUT)
Ioh = 1mA DRVDD DRVDDHigh-level output voltage V0.1Low-level output voltage Iol = 1mA 0 0.1 VOutput capacitance (internal to device) 2 pF
DIGITAL OUTPUTS LVDS INTERFACE (DA0P/M TO DA10P/M, DB0P/M TO DB10P/M, CLKOUTP/M)
VODH, High-level output differential voltage With external 100 termination +275 +350 +425 mVVODL, Low-level output differential voltage With external 100 termination. 425 350 275 mVVOCM, Output common-mode voltage 1.0 1.15 1.40 VCapacitance inside the device from each output 2 pFOutput Capacitance
to ground
(1) SCLK, SDATA, SEN function as digital input pins in serial configuration mode.(2) SDATA, SCLK have internal 200 k Ωpull-down resistor(3) SEN has internal 100 k pull-up resistor to AVDD.
Figure 2. LVDS Output Voltage Levels
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TIMING CHARACTERISTICS LVDS AND CMOS MODES
(1)
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Typical values are at 25 ° C, AVDD = 3.3V, DRVDD = 1.8V, sampling frequency = 200 MSPS, sine wave input clock, C
LOAD
=5pF
(2)
, R
LOAD
= 100
(3)
, no internal termination, LOW SPEED mode disabled, unless otherwise noted.Min and max values are across the full temperature range T
MIN
= 40 ° C to T
MAX
= 85 ° C, AVDD = 3.3V, DRVDD = 1.7V to1.9V.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
t
a
Aperture delay 0.7 1.2 1.7 ns
Aperture delay matching between two channels of the same device ± 50 ps
t
j
Aperture jitter 145 fs rms
Time to valid data after coming out of STANDBY mode 1 3
µsWake-up time Time to valid data after coming out of global powerdown 20 50
Time to valid data after stopping and restarting the input clock 10
Clock
cyclesADC Latency
(4)
Default, after reset 22
DDR LVDS MODE
(5)
t
su
Data setup time
(6)
Data valid
(7)
to zero-crossing of CLKOUTP 0.8 1.15 ns
t
h
Data hold time
(7)
Zero-crossing of CLKOUTP to data becoming invalid
(7)
0.8 1.15 ns
t
PDI
Clock propagation delay Input clock falling edge cross-over to output clock rising edge t
PDI
= 0.69 × Ts + t
delaycross-over
100 MSPS Sampling frequency 200 MSPSt
delay
4.2 5.7 7.2 nsTs = 1/Sampling frequency
Difference in t
delay
between two devices operating at samet
delay
skew ± 500 pstemperature & SVDD supply voltage.
Duty cycle of differential clock, (CLKOUTP-CLKOUTM)LVDS bit clock duty cycle 52%100 MSPS Sampling frequency 200 MSPS
Rise time measured from 100 mV to +100 mVt
RISE
, t
FALL
Data rise time, Data fall time Fall time measured from +100 mV to 100 mV 0.14 ns1MSPS Sampling frequency 200 MSPS
Rise time measured from 100 mV to +100 mVOutput clock rise time,t
CLKRISE
,
Fall time measured from +100 mV to 100 mV 0.14 nst
CLKFALL
Output clock fall time
1 MSPS Sampling frequency 200 MSPS
t
OE
Output buffer enable to data delay Time to valid data after output buffer becomes active 100 ns
PARALLEL CMOS MODE at Fs=200 MSPS
(8)
t
START
Input clock to data delay Input clock falling edge cross-over to start of data valid
(7)
2.5 ns
t
DV
Data valid time Time interval of valid data
(7)
1.7 2.7 ns
t
PDI
Clock propagation delay Input clock falling edge cross-over to output clock rising edge t
PDI
= 0.28 × Ts + t
delaycross-over
100 MSPS Sampling frequency 150 MSPSt
delay
5.5 7.5 8.5 nsTs = 1/Sampling frequency
Duty cycle of output clock, CLKOUTOutput clock duty cycle 43100 MSPS Sampling frequency 150 MSPS
Rise time measured from 20% to 80% of DRVDDt
RISE
, t
FALL
Data rise time, Data fall time Fall time measured from 80% to 20% of DRVDD 1.2 ns1Sampling frequency 200 MSPS
Rise time measured from 20% to 80% of DRVDDOutput clock rise time,t
CLKRISE
,
Fall time measured from 80% to 20% of DRVDD 0.8 nst
CLKFALL
Output clock fall time
1Sampling frequency 150 MSPS
Output buffer enable (OE) to datat
OE
Time to valid data after output buffer becomes active nsdelay
(1) Timing parameters are ensured by design and characterization and not tested in production.(2) C
LOAD
is the effective external single-ended load capacitance between each output pin and ground(3) R
LOAD
is the differential load resistance between the LVDS output pair.(4) At higher frequencies, t
PDI
is greater than one clock period and overall latency = ADC latency + 1.(5) Measurements are done with a transmission line of 100 characteristic impedance between the device and the load.Setup and hold time specifications take into account the effect of jitter on the output data and clock.(6) Data valid refers to LOGIC HIGH of +100.0mV and LOGIC LOW of -100.0mV.(7) Data valid refers to LOGIC HIGH of 1.26V and LOGIC LOW of 0.54V.(8) For Fs > 150 MSPS, it is recommended to use external clock for data capture and NOT the device output clock signal (CLKOUT).
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Table 2. LVDS Timings at Lower Sampling Frequencies
Setup Time, ns Hold Time, nsSampling Frequency, MSPS
MIN TYP MAX MIN TYP MAX
185 0.9 1.25 0.85 1.25150 1.15 1.6 1.1 1.5125 1.6 2 1.45 1.85< 100 Enable LOW SPEED mode 2 2
t
PDI
, ns
1Fs 100 Enable LOW SPEED mode MIN TYP MAX
12.6
Table 3. CMOS Timings at Lower Sampling Frequencies
Timings Specified With Respect to Input Clock
Sampling Frequency, MSPS t
START
, ns Data Valid Time, ns
MIN TYP MAX MIN TYP MAX
190 1.9 2 3170 0.9 2.7 3.7150 6 3.6 4.6
Timings Specified With Respect to CLKOUT
Sampling Frequency, MSPS Setup Time, ns Hold Time, ns
MIN TYP MAX MIN TYP MAX
150 2.8 4.4 0.5 1.2125 3.8 5.4 0.8 1.5< 100 Enable LOW SPEED mode 5 1.2
t
PDI
, ns
1Fs 100 Enable LOW SPEED mode MIN TYP MAX
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OEOEOEOEOEEOEOEOEOE O
N
N-1 N+1
22 clock cycles *
INPUT
CLOCK
CLKOUTM
CLKOUTP
OUTPUT DATA
DXP, DXM
DDR
LVDS
N-22 N-21 N-20 N-19 N-
18 N-1 N N+1 N+2
22 clock cycles *
CLKOUT
OUTPUT DATA
D0:D10
PARALLEL
CMOS
INPUT
SIGNAL
Sample
N
N+1 N+2 N+3 N+4
tPDI
ta
E Even bits D0, D2, D4...
O Odd bits D1, D3, D5...
tPDI
CLKM
CLKP
N+2
N-22 N-21 N-20 N-19
N+22
N+23 N+24
CLKOUTMCLKOUTM
CLKOUTPCLKOUTP
Output
data pair
Output
data pair
tsu
tsu
Dn* Dn+1*
th
thtsu
tsu th
th
DAnP/M
DBnP/M
DAnP/M
DBnP/M
tPDI
tPDI
CLKPCLKP
CLKMCLKM
Output
clock
Output
clock
Input
clock
Input
clock
*Dn BitsD1,D3,D5...
*Dn+1 Bits D0,D2,D4...
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Figure 3. Latency Diagram
Figure 4. LVDS Interface Timing
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CLKOUTCLKOUT
su
Dn*
CLKPCLKP
CLKMCLKM
CLKPCLKP
CLKMCLKM
InputClock
OutputClock
DAn,DBn
OutputData
InputClock
DAn,DBn
OutputClock
tPDI
tsu th
tSTART
tDV
Dn*
*Dn-BitsD0,D1,D2....ofchannel A andB
DEVICE CONFIGURATION
PARALLEL CONFIGURATION ONLY
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Figure 5. CMOS Interface Timing
ADS62C17 can be configured independently using either parallel interface control or serial interfaceprogramming.
To put the device in parallel configuration mode, keep RESET tied to high (AVDD).
Now, pins SEN, SCLK, CTRL1, CTRL2 and CTRL3 can be used to directly control certain modes of the ADC.The device can be easily configured by connecting the parallel pins to the correct voltage levels (as described inTable 3 to Table 6 . There is no need to apply reset and SDATA can be kept low.
In this mode, SEN and SCLK function as parallel interface control pins. Frequently used functions can becontrolled in this mode Power down modes, internal/external reference, selection between LVDS/CMOSinterface and output data format.
Table 4 has a brief description of the modes controlled by the four parallel pins.
Table 4. PARALLEL PIN DEFINITION
PIN CONTROLS MODES
SCLK Analog control pins (controlled by analog Internal or External referencevoltage level, see Figure 5SEN LVDS/CMOS interface and Output DataFormatCTRL1 Digital control pints (controlled by digital
Control SNRBoost, Standby and MUXlogic levels)CTRL2
mode.CTRL3
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SERIAL INTERFACE CONFIGURATION ONLY
USING BOTH SERIAL INTERFACE and PARALLEL CONTROLLS
DETAILS OF PARALLEL CONFIGURATION ONLY
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To exercise this mode, first the serial registers have to be reset to their default values and RESET pin has to bekept low.
SEN, SDATA and SCLK function as serial interface pins in this mode and can be used to access the internalregisters of the ADC.
The registers can be reset either by applying a pulse on RESET pin or by setting the < RESET > bit high. Theserial interface section describes the register programming and register reset in more detail.
For increased flexibility, a combination of serial interface registers and parallel pin controls (CTRL1 to CTRL3)can also be used to configure the device. To allow this, keep RESET low. The parallel interface control pinsCTRL1 to CTRL3 are available. After power-up, the device will automatically get configured as per the voltagesettings on these pins (Table 6). SEN, SDATA, and SCLK function as serial interface digital pins and are used toaccess the internal registers of ADC. The registers must first be reset to their default values either by applying apulse on RESET pin or by setting bit < RST > = 1. After reset, the RESET pin must be kept low. The serialinterface section describes the register programming and register reset in more detail.
The functions controlled by each parallel pin are described below. A simple way of configuring the parallel pins isshown in Figure 6 .
Table 5. SCLK Control Pin
SCLK DESCRIPTION
0
Internal reference+200mV/-0mV
(3/8)AVDD External reference± 200mV
(5/8)2AVDD External reference± 200mV
AVDD Internal reference+0mV/-200mV
Table 6. SEN Control Pin
SEN DESCRIPTION
0 Offset binary and DDR LVDS output+200mV/-0mV
(3/8)AVDD 2 s complement format and DDR LVDS output± 200mV
(5/8)2AVDD 2 s complement format and parallel CMOS output± 200mV
AVDD Offset binary and parallel CMOS output+0mV/-200mV
Table 7. CTRL1, CTRL2 and CTRL3 Pins
CTRL1 CTRL2 CTRL3 DESCRIPTION
LOW LOW LOW Normal operationLOW LOW HIGH SNRBoost enabled for Channel B
(1)
LOW HIGH LOW SNRBoost enabled for Channel A
(1)
LOW HIGH HIGH SNRBoost enabled for Channel A and B
(1)
HIGH LOW LOW Global power downHIGH LOW HIGH Channel B standby
(1) To enable & disable SNRBoost mode using the CTRL pins, reset the register bits < SNRBoost Enable -CHA > = 0 & < SNRBoost Enable - CHB > = 0.
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(5/8)AVDD
(3/8)AVDD
GND AVDD
(5/8)AVDD
(3/8)AVDD
AVDD
GND
ToParallelPin
SERIAL INTERFACE
Register Initialization (when using serial interface only)
A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
REGISTER ADDRESS REGISTERDATA
SDATA
SCLK
SEN
RESET
tSCLK tDSU tDH
tSLOADS tSLOADH
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Table 7. CTRL1, CTRL2 and CTRL3 Pins (continued)
CTRL1 CTRL2 CTRL3 DESCRIPTION
HIGH HIGH LOW Channel A standbyHIGH HIGH HIGH MUX mode of operation, Channel A and B data is multiplexed and outputon DA10 to DA0 pins.
Figure 6. Simple Scheme to Configure Parallel Pins
The ADC has a set of internal registers, which can be accessed by the serial interface formed by pins SEN(Serial interface Enable), SCLK (Serial Interface Clock) and SDATA (Serial Interface Data).
Serial shift of bits into the device is enabled when SEN is low. Serial data SDATA is latched at every falling edgeof SCLK when SEN is active (low). The serial data is loaded into the register at every 16
th
SCLK falling edgewhen SEN is low. In case the word length exceeds a multiple of 16 bits, the excess bits are ignored. Data can beloaded in multiple of 16-bit words within a single active SEN pulse.
The first 8 bits form the register address and the remaining 8 bits are the register data. The interface can workwith SCLK frequency from 20 MHz down to very low speeds (few Hertz) and also with non-50% SCLK dutycycle.
After power-up, the internal registers MUST be initialized to their default values. This can be done in one of twoways:
1. Either through hardware reset by applying a high-going pulse on RESET pin (of width greater than 10 ns) as shown in Figure 7
OR2. By applying software reset. Using the serial interface, set the < RESET > bit (D7 in register 0x00) to HIGH. This initializes internalregisters to their default values and then self-resets the < RESET > bit to low. In this case the RESET pin is kept low.
Figure 7. Serial Interface Timing
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Serial Register Readout
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Typical values at 25 ° C, min and max values across the full temperature range T
MIN
= 40C to T
MAX
= 85 ° C, AVDD = 3.3V,DRVDD = 1.8V, unless otherwise noted.
PARAMETER MIN TYP MAX UNIT
f
SCLK
SCLK frequency (= 1/ t
SCLK
) > DC 20 MHzt
SLOADS
SEN to SCLK setup time 25 nst
SLOADH
SCLK to SEN hold time 25 nst
DS
SDATA setup time 25 nst
DH
SDATA hold time 25 ns
The device includes an option where the contents of the internal registers can be read back. This may be usefulas a diagnostic check to verify the serial interface communication between the external controller and the ADC.a. First, set register bit < SERIAL READOUT > = 1. This also disables any further writes into the registers.b. Initiate a serial interface cycle specifying the address of the register (A7 A0) whose content has to be read.c. The device outputs the contents (D7 D0) of the selected register on the SDOUT pin.d. The external controller can latch the contents at the falling edge of SCLK.e. To enable register writes, reset register bit < SERIAL READOUT > =0.
The serial register readout works with both CMOS and LVDS interfaces.
When < SERIAL READOUT > is disabled, SDOUT pin is forced low by the device (and not put inhigh-impedance). If serial readout is not used, SDOUT pin has to be floated.
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00 0 0 0 0 0 0 0 0 0 0 0 0 0 1
REGISTER ADDRESS (A7:A0) = 0x00 REGISTER DATA (D7:D0) = 0x01
SDATA
SCLK
SEN
A)Enableserialreadout(<SERIAL READOUT>=1)
A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
SDATA
SCLK
SEN
SDOUT
B) Read contents of register 0x3F.
Thisregisterhasbeeninitializedwith0x04
(device is put in global power down mode)
REGISTER ADDRESS (A7:A0) = 0x3F REGISTER DATA (D7:D0 ) = XX (don’t care)
SDOUT 10 00000
Pin SDOUT functions as serial readout (<SERIAL READOUT> = 1)
0
Pin SDOUT is NOT in high-impedance state; it is forced low by the device (<SERIAL READOUT> = 0)
RESET TIMING (WHEN USING SERIAL INTERFACE ONLY)
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Figure 8. Serial Readout
Typical values at 25 ° C, min and max values across the full temperature range T
MIN
= 40 ° C to T
MAX
= 85 ° C, unless otherwisenoted.
PARAMETER CONDITIONS MIN TYP MAX UNIT
t
1
Power-on delay Delay from power-up of AVDD and DRVDD to RESET pulse active 1 nst
2
Reset pulse width Pulse width of active RESET signal 10 ns1
(1)
µst
3
Register write delay Delay from RESET disable to SEN active 100 ns
(1) The reset pulse is needed only when using the serial interface configuration. If the pulse width is greater than 1usec, the device couldenter the parallel configuration mode briefly and then return back to serial interface mode.
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NOTE: A high-going pulse on RESET pin is required in serial interface mode in case of initialization through hardware reset.For parallel interface operation, RESET has to be tied permanently HIGH.
Figure 9. Reset Timing Diagram
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SERIAL REGISTER MAP
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Table 8. Summary of Functions Supported by Serial Interface
(1)
REGISTER
REGISTER FUNCTIONSADDRESS
A7 - A0
D7 D6 D5 D4 D3 D2 D1 D0IN HEX
< RESET >
< SERIAL00 0 0 0 0 0 0Software
READOUT >Reset
< ENABLE
LOW20 0 0 0 0 0 0 0SPEED
mode >
< REF >
< STAND3F 0 0 0 0 0BY >Internal or external reference40 0 0 0 0 < POWER DOWN MODES >
< LVDS
CMOS >41 0 0 0 0 0 0 0Output
interface44 < CLKOUT EDGE CONTROL > 0 0
< DATA FORMAT >< ENABLE50 0 INDEPENDENT 0 0 0 02s comp or offsetCHANNEL CONTROL >
binary51 < CUSTOM PATTERN LOW > 0 0 052 0 0 < CUSTOM PATTERN HIGH >
< OFFSET CORRECTION53 0 ENABLE Common/Ch 0A >
< GAIN PROGRAMMABILITY Common/Ch A > < OFFSET CORRECTION TIME55
0 to 6 dB in 0.5 dB steps CONSTANT Common/ Ch A >
56 < SNRBoost Coeff 1 Common/ Ch A >< SNRBoost Coeff 2 Common/ Ch A >
< FINE GAIN ADJUST Common/ Ch A >57 0
+0.001 dB to +0.134 dB, in 128 steps
< SNRBoost
Enable 59 0 0 0 0 0 0 0
Common/ Ch A>
62 0 0 0 0 0 < TEST PATTERNS - Common/ Ch A >
63 0 0 < OFFSET PEDESTAL Common/ Ch A >
< OFFSET CORRECTION66 0 0 0 0 0 0 0ENABLE Ch B >
< GAIN PROGRAMMABILITY Ch B > < OFFSET CORRECTION TIME68
0 to 6 dB in 0.5 dB steps CONSTANT Ch B >
69 < SNRBoost Coeff 1 Ch B > < SNRBoost Coeff 2 Ch B >
< FINE GAIN ADJUST Ch B >6A 0
+0.001 dB to +0.134 dB, in 128 steps
< SNRBoost6C 0 0 0 0 0 0 0
Enable ChB >
75 0 0 0 0 0 < TEST PATTERNS - Ch B >
76 0 0 < OFFSET PEDESTAL Ch B >
(1) Multiple functions in a register can be programmed in a single write operation.
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D000 < RESET > 0 0 0 0 0 0 < SERIAL
READOUT >Software Reset
D7 < RESET >1 Software reset applied resets all internal registers and self-clears to 0.
D0 < SERIAL READOUT >0 Serial readout disabled. SDOUT is forced high or low by the device (and not out in high impedancestate).
1 Serial readout enabled, Pin SDOUT functions as serial data readout. This mode is available only withCMOS output interface. With LVDS interface, pin 56 becomes CLKOUTM.
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D020 0 0 0 0 0 < ENABLE LOW 0 0SPEED MODE >
D2 < ENABLE LOW SPEED MODE >0 LOW SPEED mode disabled. Use for sampling frequency > 100 MSPS.1 Enable LOW SPEED mode for sampling frequencies < = 100 MSPS.
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D03F 0 < REF > 0 0 0< STANDBY > 0
D6-D5 < REF > Internal or external reference selection01 Internal reference enabled11 External reference enabled
D1 < STANDBY >0 Normal operation1 ADC is powered down for both channels. Internal references, output buffers are active. This results inquick wake-up time from standby.
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D040 0 0 0 0 POWER DOWN MODES
D3-D0 < POWER DOWN MODES >0000 Pins CTRL1, CTRL2 & CTRL3 determine power down modes.1000 Normal operation1001 Output buffer disabled for channel B1010 Output buffer disabled for channel A1011 Output buffer disabled for channel A and B1100 Global power down1101 Channel B standby1110 Channel A standby1111 Multiplexed mode, MUX (only with CMOS interface)Channel A and B data is multiplexed and output on DA10 to DA0 pins.
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D041 < LVDS 0 0 0 0 00 0CMOS >
D7 < LVDS CMOS >0 Parallel CMOS interface1 DDR LVDS interface
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D044 < CLKOUT EDGE CONTROL > 0 0Output clock edge control
LVDS Interface
D7-D5 < CLKOUT POSN > Output clock rising edge position000, 100 Default output clock position (refer to timing specification table)101 Rising edge shifted by + (4/26)Ts110 Rising edge aligned with data transition111 Rising edge shifted by (4/26)TsD4-D2 < CLKOUT POSN > Output clock falling edge position000, 100 Default output clock position (refer to timing specification table)101 Falling edge shifted by + (4/26)Ts110 Falling edge aligned with data transition111 Falling edge shifted by (4/26)Ts
CMOS INterface
D7-D5 < CLKOUT POSN > Output clock rising edge position000, 100 Default output clock position (refer to timing specification table)101 Rising edge shifted by + (4/26)Ts110 Rising edge shifted by (6/26)Ts111 Rising edge shifted by (4/26)TsD4-D2 < CLKOUT POSN > Output clock falling edge position000, 100 Default output clock position (refer to timing specification table)101 Falling edge shifted by + (4/26)Ts110 Falling edge shifted by (6/26)Ts111 Falling edge shifted by (4/26)Ts
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D050 0 < ENABLE INDEPENDENT 0 0 0 < DATA FORMAT > 0CHANNEL CONTROL > 2s complement or offset binary 0
D6 < ENABLE INDEPENDENT CHANNEL CONTROL >0Common control both channels use common control settings for test patterns, offset correction,gain, gain correction and SNRBoost functions. These settings can be specified in a single set ofregisters.
1Independent control both channels can be programmed with independent control settings for testpatterns, offset correction and SNRBoost functions. Separate registers are available for eachchannel.
D2-D1 < DATA FORMAT >10 2s complement
11 Offset binary
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D051 < Custom Pattern Low > 00 052 0 0 < Custom Pattern High >
D7-D3 < CUSTOM LOW >5 lower bits of custom pattern available at the output instead of ADC dataD5-D0 < CUSTOM HIGH >6 upper bits of custom pattern available at the output instead of ADC data
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D053 0 < OFFSET CORRECTION ENABLE 0 0 0 00 0Common/Ch A >Offset correction enable
D6 < OFFSET CORRECTION ENABLE Common/Ch A >Offset correction enable control for both channels ( with common control) or for channel A only ( withindependent control).0 Offset correction disabled1 Offset correction enabled
See Offset Correction
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D055 < GAIN PROGRAMMABILITY Common/Ch A > < OFFSET CORR TIME CONSTANT Common/Ch A >Offset correction time constant
D7-D4 < GAIN PROGRAMMABILITY Common/Ch A >Gain control for both channels (with common control) or for channel A only (with independentcontrol).
0000 0 dB gain, default after reset0001 0.5 dB gain0010 1.0 dB gain0011 1.5 dB gain0100 2.0 dB gain0101 2.5 dB gain0110 3.0 dB gain0111 3.5 dB gain1000 4.0 dB gain1001 4.5 dB gain1010 5.0 dB gain1011 5.5 dB gain1100 6.0 dB gain
D3-D0 < OFFSET CORR TIME CONSTANT Common/Ch A >Correction loop time constant in number of clock cycles.Applies to both channels (with common control) or for channel A only (with independent control).0000 256 k0001 512 k0010 1 M0011 2 M0100 4 M0101 8 M0110 16 M0111 32 M1000 64 M1001 128 M1010 256 M1011 512 M
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D056 < SNRBoost Coeff 1 Common/CH A > < SNRBoost Coeff 2 Common/CH A >
See SNR enhancement using SNRBoost
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D057 0 < FINE GAIN ADJUST Common/Ch A > +0.001 dB to +0.134 dB, in 128 steps
Using the FINE GAIN ADJUST register bits, the channel gain can be trimmed in fine steps. The trim is onlyadditive, has 128 steps & a range of 0.134dB. The relation between the FINE GAIN ADJUST bits & the trimmedchannel gain is:
ΔChannel Gain = 20 × log10[1 + (FINE GAIN ADJUST/8192)]
Note that the total device gain = ADC gain + ΔChannel gain. The ADC gain is determined by register bits < GAINPROGRAMMABILITY>
A7 A0 IN D7 D6 D5 D4 D3 D2 D1 D0HEX
59 0 0 0 0 0 0 0 < SNRBoost Enable CH A >
D0 < SNRBoost Enable CH A >SNRBoost control for both channels ( with common control) or for channel A only ( with independentcontrol).
0 SNRBoost disabled1 SNRBoost enabled
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D062 0 0 0 0 0 < TEST PATTERNS >
D2-D0 < TEST PATTERNS > Test Patterns to verify data capture.Applies to both channels ( with common control) for channel A only ( with independent control)000 Normal operation001 Outputs all zeros010 Outputs all onesOutputs toggle pattern011
Output data < D10:D0 > alternates between 01010101010 and 10101010101 every clock cycle.Outputs digital ramp100
Output data increments by one LSB (12-bit) every 8th clock cycle from code 0 to code 2047.101 Outputs custom pattern (use registers 0x51, 0x52 for setting the custom pattern)110 Unused
111 Unused
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D063 0 0 < OFFSET PEDESTAL Common/Ch A >
D5-D0 < OFFSET PEDESTAL Common/Ch A >When the offset correction is enabled, the final converged value after the offset is corrected will bethe ADC mid-code value. A pedestal can be added to the final converged value by programmingthese bits. See " Offset Correction " in application section.Applies to both channels ( with common control) or for channel A only ( with independent control).011111 PEDESTAL = 31 LSB011110 PEDESTAL = 30 LSB011101 PEDESTAL = 29 LSB....
000000 PEDESTAL = 0 LSB....
111111 PEDESTAL = 1 LSB111110 PEDESTAL = 2 LSB....
100000 PEDESTAL = 32LSB
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D066 0 < OFFSET CORRECTION ENABLE 0 0 0 0 0 0 CH B >Offset correction enable
D6 < OFFSET CORRECTION ENABLE CH B >Offset correction enable control for channel B ( only with independent control).0 offset correction disabled1 offset correction enabled
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D068 < GAIN PROGRAMMABILITY CH B > < OFFSET CORR TIME CONSTANT CH B >Offset correction time constant
D7-D4 < GAIN CH B > Gain programmability in 0.5 dB stepsApplies to channel B ( only with independent control).0000 0 dB gain, default after reset0001 0.5 dB gain0010 1.0 dB gain0011 1.5 dB gain0100 2.0 dB gain0101 2.5 dB gain0110 3.0 dB gain0111 3.5 dB gain1000 4.0 dB gain1001 4.5 dB gain1010 5.0 dB gain1011 5.5 dB gain1100 6.0 dB gain
D3-D0 < OFFSET CORR TIME CONSTANT CH B > Time constant of correction loop in number of clockcycles.
Applies to channel B ( only with independent control)0000 256 k0001 512 k0010 1 M0011 2 M0100 4 M0101 8 M0110 16 M0111 32 M1000 64 M1001 128 M1010 256 M1011 512 M
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D069 < SNRBoost Coeff 1 CH B > < SNRBoost Coeff 2 CH B >
See SNR enhancement using SNRBoost
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D06A < GAIN CORRECTION CH B > +0.001 dB to +0.134 dB, in 128 steps
Using the FINE GAIN ADJUST register bits, the channel gain can be trimmed in fine steps. The trim is onlyadditive, has 128 steps & a range of 0.134dB. The relation between the FINE GAIN ADJUST bits & the trimmedchannel gain is:
ΔChannel Gain = 20 × log10[1 + (FINE GAIN ADJUST/8192)]
Note that the total device gain = ADC gain + ΔChannel gain. The ADC gain is determined by register bits < GAINPROGRAMMABILITY>
A7 A0 IN D7 D6 D5 D4 D3 D2 D1 D0HEX
6C 0 0 0 0 0 00< SNRBoost Enable CH B >
D0 < SNRBoost Enable CH B >SNRBoost control for channel B ( only with independent control).0 SNRBoost disabled1 SNRBoost enabled
A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D075 0 0 0 < TEST PATTERNS CH B >
D2-D0 < TEST PATTERNS > Test Patterns to verify data captureApplies to both channels ( with common control) for channel A only ( with independent control)000 Normal operation001 Outputs all zeros010 Outputs all onesOutputs toggle pattern011
Output data < D10:D0 > alternates between 01010101010 and 10101010101 every clock cycle.Outputs digital ramp100
Output data increments by one LSB (12-bit) every 8th clock cycle from code 0 to code 2047.101 Outputs custom pattern (use registers 0x51, 0x52 for setting the custom pattern)110 Unused
111 Unused
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A7 A0 IN HEX D7 D6 D5 D4 D3 D2 D1 D076 0 0 < OFFSET PEDESTAL Common/Ch A >
D5-D0 < OFFSET PEDESTAL Ch B >When the offset correction is enabled, the final converged value after the offset is corrected will bethe ADC mid-code value. A pedestal can be added to the final converged value by programmingthese bits. See " Offset Correction " in application section.Applies to both channels ( with common control) or for channel A only ( with independent control).011111 PEDESTAL = 31 LSB011110 PEDESTAL = 30 LSB011101 PEDESTAL = 29 LSB....
000000 PEDESTAL = 0 LSB....
111111 PEDESTAL = 1 LSB111110 PEDESTAL = 2 LSB....
100000 PEDESTAL = 32LSB
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Figure 10. Pin Configuration
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PIN NO.
PIN
DESCRIPTIONOF
TYPENAME NUMBER
PINS
AVDD 16, 33, 34 3 I Analog power supplyAGND 17,18,21,24, 8 I Analog ground27,28,31,32CLKP, CLKM 25, 26 2 I Differential clock inputINP_A, INM_A 29, 30 2 I Differential analog input, Channel AINP_B, INM_B 19, 20 2 I Differential analog input, Channel BVCM 23 1 IO Internal reference mode Common-mode voltage output.External reference mode Reference input. The voltage forced on this pin sets theinternal references.RESET 12 1 I Serial interface RESET input.When using the serial interface mode, the user must initialize internal registersthrough hardware RESET by applying a high-going pulse on this pin or by usingsoftware reset option. Refer to Serial Interface section.In parallel interface mode, the user has to tie RESET pin permanently high. (SCLKand SEN are used as parallel control pins in this mode)The pin has an internal 100 k pull-down resistor.SCLK 13 1 I This pin functions as serial interface clock input when RESET is low.
It controls selection of internal or external reference when RESET is tied high. SeeTable 5 for detailed information.The pin has an internal 100 k pull-down resistor.SDATA 14 1 I Serial interface data input.The pin has an internal 100 k pull-down resistor.The pin has no function in parallel interface mode and can be tired to ground.SEN 15 1 I This pin functions as serial interface enable input when RESET is low.It controls selection of data format and interface type when RESET is tied high.See Table 6 for detailed information.The pin has an internal 100 k pull-up resistor to AVDDSDOUT 64 1 O This pin functions as serial interface register readout, when the < SERIALREADOUT > bit is enabled.When < SERIAL READOUT > = 0, this pin forces logic LOW & is not tri-stated.CTRL1 35 1 I
Digital control input pins. Together, they control SNRBoost control and power downCTRL2 36 1 I
modes.CTRL3 37 1 ICLKOUTP 57 1 O Differential output clock, trueCLKOUTM 56 1 O Differential output clock, complementDA0P, DA0M 2 O Differential output data pair, D0 and 0 multiplexed Channel ADA2P, DA2M 2 O Differential output data D1 and D2 multiplexed, true Channel ADA4P, DA4M 2 O Differential output data D3 and D4 multiplexed, true Channel ADA6P, DA6M 2 O Differential output data D5 and D6 multiplexed, true Channel ADA8P, DA8M 2 O Differential output data D7 and D8 multiplexed, true Channel ADA10P, DA10M 2 O Differential output data D9 and D10 multiplexed, true Channel ARefer toFigure 10DB0P, DB0M 2 O Differential output data pair, D0 and 0 multiplexed Channel BDB2P, DB2M 2 O Differential output data D1 and D2 multiplexed, true Channel BDB4P, DB4M 2 O Differential output data D3 and D4 multiplexed, true Channel BDB6P, DB6M 2 O Differential output data D5 and D6 multiplexed, true Channel BDB8P, DB8M 2 O Differential output data D7 and D8 multiplexed, true Channel BDB10P, DB10M 2 O Differential output data D9 and D10 multiplexed, true Channel BDRVDD 1,38,48,58 4 I Output buffer supply
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PIN CONFIGURATION (CMOS INTERFACE) ADS62C17
AGND
AGND
INP_B
NC
INM_A
AGND
AGND
CLKP
CLKM
UNUSED
DRVDD
CTRL 3
DB0
SDOUT
DRGND
DB 4
DB 5
DB 7
DB 6
DB 9
DB 8
DB10
DA10
DA8
DA9
DA3
DA4
DA1
DA2
DA0
AVDD
SDATA
SCLK
CTRL 1
CTRL 2
AGND
AVDD
INM_B
AGND
INP_A
AVDD
AGND
AGND
18 19 20 21 22 23 24 3130
2928272625
63 62 60 59 58 57 56 5052535455 51
64 61
2
3
4
5
6
7
9
10
8
11
12
13
14
15
1
16
36
35
34
48
47
46
45
44
43
42
41
40
39
38
37
DRGND
DRVDD
DRGND
DRVDD
DB3
DB2
DA7
DA6
32
NC
NC
NC
NC
DA5
NC
DB1
NC
CLKOUT
PAD(ConnectedtoDRGND)
DRVDD
RESET
SEN
VCM
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PIN NO.
PIN
DESCRIPTIONOF
TYPENAME NUMBER
PINS
DRGND 39,49,59,PAD 4 I Output buffer groundNC Refer to Do not connectFigure 10
Figure 11. Pin Configuration
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PIN NO.
PIN
DESCRIPTIONOF
TYPENAME NUMBER
PINS
AVDD 16, 33, 34 3 I Analog power supplyAGND 17,18,21,24, 8 I Analog ground27,28,31, 32CLKP, CLKM 25, 26 2 I Differential clock inputINP_A, INM_A 29, 30 2 I Differential analog input, Channel AINP_B, INM_B 19, 20 2 I Differential analog input, Channel BVCM 23 1 IO Internal reference mode Common-mode voltage output.External reference mode Reference input. The voltage forced on this pin setsthe internal references.RESET 12 1 I Serial interface RESET input.When using the serial interface mode, the user MUST initialize internal registersthrough hardware RESET by applying a high-going pulse on this pin or by usingsoftware reset option. Refer to SERIAL INTERFACE section.In parallel interface mode, the user has to tie RESET pin permanently high.(SDATA and SEN are used as parallel control pins in this mode)The pin has an internal 100 k pull-down resistor.SCLK 13 1 I This pin functions as serial interface clock input when RESET is low.
It controls selection of internal or external reference when RESET is tied high.See Table 5 for detailed information.The pin has an internal 100 k pull-down resistor.SDATA 14 1 I Serial interface data input.The pin has an internal 100 k pull-down resistor.The pin has no function in parallel interface mode and can be tired to ground.SEN 15 1 I This pin functions as serial interface enable input when RESET is low.It controls selection of data format and interface type when RESET is tied high.See Table 6 for detailed information.The pin has an internal 100 k pull-up resistor to AVDDSDOUT 64 1 O This pin functions as serial interface register readout, when the < SERIALREADOUT > bit is enabled.When < SERIAL READOUT > = 0, this pin forces logic LOW & is not tri-stated.CTRL1 35 1 I
Digital control input pins. Together, they control SNRBoost control & power downCTRL2 36 1 I
modes.CTRL3 37 1 ICLKOUT 57 1 O CMOS output clockDA0, DA10 11 O Channel A 11-bit ADC output data bits, CMOS levelsRefer to Figure 11DB0-DB10 11 O Channel B 11-bit ADC output data bits, CMOS levelsDRVDD 1,38,48,58 4 I Output buffer supplyDRGND 39,49,59,PAD 3 I Output buffer groundNC Refer to Figure 11 Do not connect
32 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated
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TYPICAL CHARACTERISTICS
-140
-120
-100
-80
-60
-40
-20
0
0 10 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Amplitude-dB
Ain=-1dBFS,
SFDR=83.8dBc,
SNR=67dBFS,
SINAD=66.9dBFS,
THD=83.3dBc
-140
-120
-100
-80
-60
-40
-20
0
0 10 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Amplitude-dB
Ain=-1dBFS,
SFDR=83.6dBc,
SNR=66.8dBFS,
SINAD=66.8dBFS,
THD=83dBc
-140
-120
-100
-80
-60
-40
-20
0
010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Amplitude-dB
Ain=-1dBFS,
SFDR=74.2dBc,
SNR=66.3dBFS,
SINAD=65.7dBFS,
THD=73.5dBc
ADS62C17
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..................................................................................................................................................................................................... SLAS631 APRIL 2009
All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
FFT for 20 MHz INPUT SIGNAL
Figure 12.
FFT for 60 MHz INPUT SIGNAL
Figure 13.
FFT for 170 MHz INPUT SIGNAL
Figure 14.
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010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
Ain=-1dBFS,
SFDR=71.7dBc,
SNR=65.7dBFS,
SINAD=64.8dBFS,
THD=70.8dBc
-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Ain=-7dBFSeachtone,
Fin1=185MHz,
Fin2=190MHz,
AMD3=87.5dBFS,
SFDR=90dBFS
-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Ain=-35dBFSeachtone,
Fin1=185MHz,
Fin2=190MHz,
IMD3=107dBFS,
SFDR=104dBFS
ADS62C17
SLAS631 APRIL 2009 .....................................................................................................................................................................................................
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TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
FFT for 270 MHZ INPUT SIGNAL
Figure 15.
FFT for 2-TONE INPUT SIGNAL(INTERMODULATION DISTORTION)
Figure 16.
FFT for 2-TONE INPUT SIGNAL(INTERMODULATION DISTORTION)
Figure 17.
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-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Ain=-36dBFS,
SNRBoostCoeff1=0x0,
,
SFDR=51.8dBc,
THD=51dBc,
SNRover5MBW(47.5Mto52.5M) ,
SNRBoostCoeff2=0x0
=88.4dBFS
SNRover10MBW(45Mto55M)=84.5dBFS,
SNRover15MBW(42.5Mto57.5M)=82.5dBFS
-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Ain=-36dBFS,
SNRBoostCoeff1=0xF,
,
SFDR=52dBc,
THD=52.8dBc,
SNRover20MBW(40Mto60M)
SNRBoostCoeff2=0x1
=80.9dBFS
-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Ain=-36dBFS,
SNRBoostCoeff1=0xD,
,
SFDR=52.7dBc,
THD=53.1dBc,
SNRover30MBW(35Mto65M)
SNRBoostCoeff2=0x3
=78.4dBFS
ADS62C17
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..................................................................................................................................................................................................... SLAS631 APRIL 2009
TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
FFT with SNRBOOST ENABLED
for5MHz, 10MHZ, and 15 MHz BANDWIDTHS, Fin = 150 MHz, Fcenter = Fs/4
Figure 18.
FFT with SNRBOOST ENABLED
for20 MHz BANDWIDTH, Fin = 150 MHz, Fcenter = Fs/4
Figure 19.
FFT with SNRBOOST ENABLED
for30MHz, BANDWIDTH, Fin = 150 MHz, Fcenter = Fs/4
Figure 20.
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-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
010 20 30 40 50 60 70 80 90 100
f-Frequency-MHz
Ain=-36dBFS,
SNRBoostCoeff1=0xD,
,
SFDR=54.4dBc,
THD=53.8dBc,
SNRover40MBW(30Mto70M)
SNRBoostCoeff2=0x3
=75.8dBFS
78
80
82
84
86
88
90
SNR
(37.5Mto42.5M)
SNR
(42.5Mto47.5M)
SNR
(47.5Mto52.5M)
SNR
(52.5Mto57.5M)
SNR
(57.5Mto62.5M)
SNR-dBFS
SNRBoostEnabled
SNRBoostDisabled
Ain=-36dBFS,
Fin=150.2MHz,
,
Optimizedfor20MHzBandwidth,
SNRover20MBW(SNRBoostDisabled) ,
SNRBoostCoeff2=0x1
=73.7dBFS
SNRover20MBW( )=80.9dBFSSNRBoostEnabled
66
70
74
78
82
86
90
0 100 200 300 400 500
InputFrequency-MHz
SFDR-dBc
ADS62C17
SLAS631 APRIL 2009 .....................................................................................................................................................................................................
www.ti.com
TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
FFT with SNRBOOST ENABLED
for40MHz, BANDWIDTH, Fin = 150 MHz, Fcenter = Fs/4
Figure 21.
SNR with SNRBOOST ENABLEand DISABLED SFDR ACROSS INPUT FREQUENCY
Figure 22. Figure 23.
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63
64
65
66
67
68
0 100 200 300 400 500
InputFrequency-MHz
SNR-dBFS
68
72
76
80
84
88
92
0 100 200 300 400 500
InputFrequency-MHz
Gain=0dB
Gain=2dB
Gain=5dB
Gain=6dB
Gain=3dB
Gain=4dB
SFDR-dBc
Gain=1dB
62
63
64
65
66
67
68
0 50 100 150 200 250 300 350 400 450
InputFrequency-MHz
Gain=0dB
Gain=1dB
Gain=2dB
Gain=3dB
Gain=4dB
Gain=6dB
500
SINAD-dBFS
Gain=5dB
40
50
60
70
80
90
100
-40 -35 -30 -25 -20 -15 -10 -5 0
65
65.5
66
66.5
67
67.5
68
SFDR-dBc
SNR-dBFS
SFDR-dBc
Input Amplitude-dBFs
SNR-dBFS
ADS62C17
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..................................................................................................................................................................................................... SLAS631 APRIL 2009
TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
SNR ACROSS INPUT FREQUENCY SFDR ACROSS GAIN
Figure 24. Figure 25.
PERFORMANCE ACROSS INPUT AMPLITUDESINAD SCROSS GAIN SINGLE TONE
Figure 26. Figure 27.
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80
81
82
83
84
85
86
1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7
InputCommonModeVoltage-V
65
65.5
66
66.5
67
67.5
68
SFDR-dBc
SNR-dBFS
SFDR-dBc
SNR-dBFS
InputFrequency=60
82
86
90
94
98
102
106
110
-7 -12 -18 -24 -30 -36 -42 -48
Input Amplitudeofeachtone-dBFS
SFDR-dBFS
IMD3,SFDR,dBFS
IMD3-dBFS
65.5
66
66.5
67
67.5
-40 -25 25 55 85
AVDD=3V
AVDD=3.3V
AVDD=3.6V
SNR-dBFS
T -Free-AirTemperature-°C
A
InputFrequency=60MHz
82
83
84
85
86
87
88
89
90
-40 -25 25 55 85
AVDD=3V
AVDD=3.3V
AVDD=3.6V
InputFrequency=60MHz
SFDR-dBc
T -Free-AirTemperature-°C
A
ADS62C17
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TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
INTER-MODULATION with 2-TONE INPUT PERFORMANCE ACROSS INPUTACROSS INPUT AMPLITUDE COMMON-MODE VOLTAGE
Figure 28. Figure 29.
SFDR ACROSS TEMPERATURE SNR ACROSS TEMPERATUREvs vsAVDD SUPPLY AVDD SUPPLY
Figure 30. Figure 31.
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83
84
85
86
87
1.6 1.7 1.8 1.9
DRVDD-SupplyVoltage-V
66
66.5
67
67.5
68
SFDR-dBc
SNR-dBFS
InputFrequency=60MHz,
AVDD=3.3V
SFDR-dBc
SNR,dBFS
81
82
83
84
85
InputClock Amplitude,V Differential
PP
66
66.5
67
67.5
68
SFDR-dBc
SNR-dBFS
SFDR-dBc
SNR,dBFS
0.11 0.31 0.52 0.73 0.94 1.15 1.36 1.57 1.77 1.97 2.15
InputFrequency=60MHz
82
83
84
85
86
1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7
VoltageForcedonVCMPin-V
66
66.5
67
67.5
68
SFDR-dBc
SNR-dBFS
SNR-dBFS
SFDR-dBc
85
86
87
88
89
30 35 40 45 50 55 60 65 70
InputClockDutyCycle-%
66
66.5
67
67.5
68
SFDR-dBc
SNR-dBFS
InputFrequency=20MHz
SFDR-dBc
SNR,dBFS
ADS62C17
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..................................................................................................................................................................................................... SLAS631 APRIL 2009
TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
PERFORMANCE ACROSS PERFORMANCE ACROSSDRVDD SUPPLY VOLTAGE INPUT CLOCK AMPLITUDE
Figure 32. Figure 33.
PERFORMANCEPERFORMANCE ACROSS ACROSSINPUT CLOCK DUTY CYCLE EXTERNAL REFERENCE MODE
Figure 34. Figure 35.
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0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
025 50 75 100 125 150 175 200
Samplingfrequency-MSPS
TotalPower-W
CMOS
(NoloadCapacitance)
LVDS
-70
-65
-60
-55
-50
-45
-40
-35
-30
20 40 60 80 100 130 170 230 270
Common-ModeFrequency-MHz
CMRR-dB
0.4
20.4
60.4
80.4
100.4
120.4
140.4
0 25 50 75 100 125 150 175 200
SamplingFrequency-MSPS
40.4
DRVDDCurrent-mA
Fin=2.5MHz
CMOS15pF
LoadCapacitance
LVDS
CMOS
NoloadCapacitance
ADS62C17
SLAS631 APRIL 2009 .....................................................................................................................................................................................................
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TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
CMRR
vs POWER DISSIPATION ACROSSFREQUENCY SAMPLING FREQUENCY
Figure 36. Figure 37.
DRVDD CURRENT ACROSSSAMPLING FREQUENCY
Figure 38.
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200
180
160
140
120
100
80
20 50 100 150 200 250 300 350 400 450 500
70 75 80 85 90 95
SamplingFrequency-MSPS
200
180
160
140
120
100
80
SamplingFrequency-MSPS
6560
100 200 300 400 500 600 700 800
70 75 80 85 90
20
ADS62C17
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..................................................................................................................................................................................................... SLAS631 APRIL 2009
TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
SFDR CONTOUR
0 dB GAINup to 500 MHz
Figure 39.
SFDR CONTOUR
6 dB GAINup to 800 MHz
Figure 40.
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200
180
160
140
120
100
80
20 50 100 150 200 250 300 350 400 450 500
63 64 65 66 67
SamplingFrequency-MSPS
63.5 64.5 65.5 66.5
200
180
160
140
120
100
80
SamplingFrequency-MSPS
60 60.5
100 200 300 400 500 600 700 800
61 62 63 64 65
20
61.5 62.5 63.5 65.564.5
ADS62C17
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TYPICAL CHARACTERISTICS (continued)All plots are at 25 ° C, AVDD = 3.3 V, DRVDD = 1.8 V, sampling frequency = 200 MSPS, sine wave input clock. 1.5 VPPdifferential clock amplitude, 50% clock duty cycle, 1 dBFS differential analog input, SNRBoost disabled, internal referencemode, 0 dB gain, LVDS output interface (unless otherwise noted)
SNR CONTOUR
0 dB GAINup to 500 MHz
Figure 41.
SNR CONTOUR
6 dB GAINup to 800 MHz
Figure 42.
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APPLICATION INFORMATION
THEORY OF OPERATION
ANALOG INPUT
INP
INM
10 W
RCRFilter
Sampling
capacitor
Sampling
switch
Sampling
switch
Ron
15 W
Ron
100 W
3pF
Lpkg~ 2 nH Sampling
capacitor
Ron
10 W
Lpkg~ 2 nH
C
~1pF
bond
R
200 W
R
200 W
C
~1pF
bond
3pF
100 W
C2
0.5pF
C1
0.25pF
C2
0.5pF
15 W
C
2pF
samp
C
2pF
samp
10 W
Drive Circuit Requirements
ADS62C17
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..................................................................................................................................................................................................... SLAS631 APRIL 2009
ADS62C17 is a low power 11-bit pipeline A/D converters with maximum sampling rate up to 200 MSPS.
At every falling edge of the input clock, the analog input signal of each channel is sampled simultaneously. Thesampled signal in each channel is converted by a pipeline of low resolution stages. In each stage, the sampledand held signal is converted by a high speed, low resolution flash sub-ADC. The difference (residue) between thestage input and its quantized equivalent is gained and propagates to the next stage. At every clock, eachsucceeding stage resolves the sampled input with greater accuracy. The digital outputs from all stages arecombined in a digital correction logic block and processed digitally to create the final 11 bit code, after a datalatency of 22 clock cycles.
The digital output is available as either DDR LVDS or parallel CMOS and coded in either straight offset binary orbinary 2s complement format.
The dynamic offset of the first stage sub-ADC limits the maximum analog input frequency to about 500MHz (with2V pp amplitude) and about 800MHz (with 1V pp amplitude).
The analog input consists of a switched-capacitor based differential sample and hold architecture.
This differential topology results in very good AC performance even for high input frequencies at high samplingrates. The INP and INM pins have to be externally biased around a common-mode voltage of 1.5V, available onVCM pin. For a full-scale differential input, each input pin INP, INM has to swing symmetrically betweenVCM + 0.5V and VCM 0.5V, resulting in a 2Vpp differential input swing.
Figure 43. Analog Input Circuit
For optimum performance, the analog inputs must be driven differentially. This improves the common-modenoise immunity and even order harmonic rejection. A 5 to 15 resistor in series with each input pin isrecommended to damp out ringing caused by package parasitic.
SFDR performance can be limited due to several reasons - the effect of sampling glitches (described below),non-linearity of the sampling circuit & non-linearity of the quantizer that follows the sampling circuit.
Depending on the input frequency, sample rate & input amplitude, one of these plays a dominant part in limitingperformance.
At very high input frequencies (> about 300 MHz), SFDR is determined largely by the device s sampling circuitnon-linearity. At low input amplitudes, the quantizer non-linearity usually limits performance.
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0.01
0.10
1
10
100
0 100 200 300 400 500 600 700 800 900 1000
f-Frequency-MHz
Resistance-kW
ADS62C17
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Glitches are caused by the opening & closing of the sampling switches. The driving circuit should present a lowsource impedance to absorb these glitches. Otherwise, this could limit performance, mainly at low inputfrequencies (up to about 200 MHz). It is also necessary to present low impedance ( < 50 ) for the commonmode switching currents. This can be achieved by using two resistors from each input terminated to the commonmode voltage (VCM).
The device includes an internal R-C filter from each input to ground. The purpose of this filter is to absorb thesampling glitches inside the device itself. The cut-off frequency of the R-C filter involves a trade-off.
A lower cut-off frequency (larger C) absorbs glitches better, but it reduces the input bandwidth. On the otherhand, with a higher cut-off frequency (smaller C), bandwidth support is maximized. But now, the samplingglitches need to be supplied by the external drive circuit. This has limitations due to the presence of the packagebond-wire inductance.
In ADS62C17, the R-C component values have been optimized while supporting high input bandwidth (up to 700MHz). However, in applications with input frequencies up to 200-300MHz, the filtering of the glitches can beimproved further using an external R-C-R filter (as shown in Figure 46 and Figure 47 ).
In addition to the above, the drive circuit may have to be designed to provide a low insertion loss over thedesired frequency range and matched impedance to the source. While doing this, the ADC input impedancemust be considered. Figure 44 and Figure 45 show the impedance (Zin = Rin || Cin) looking into the ADC inputpins.
Figure 44. ADC Analog Input Resistance (Rin) Across Frequency
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1
1.5
2
2.5
3
3.5
4
4.5
0 100 200 300 400 500 600 700 800 900 1000
f-Frequency-MHz
Capacitance-pF
Driving Circuit
ADS62C17
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Figure 45. ADC Analog Input Capacitance (Cin) Across Frequency
Two example driving circuit configurations are shown in Figure 46 and Figure 47 one optimized for lowbandwidth (low input frequencies) and the other one for high bandwidth to support higher input frequencies.
In Figure 46 , an external R-C-R filter using 22pF has been used. Together with the series inductor (39nH), thiscombination forms a filter and absorbs the sampling glitches. Due to the large capacitor (22pF) in the R-C-R andthe 15 resistors in series with each input pin, the drive circuit has low bandwidth and supports low inputfrequencies ( < 100MHz).
To support high input frequencies (up to about 300MHz, see Figure 47 ), the capacitance used in the R-C-R isreduced to 3.3pF and the series inductors are shorted out. Together with the lower series resistors (5 ), thisdrive circuit provides high bandwidth and supports high input frequencies.
Transformers such as ADT1-1WT or ETC1-1-13 can be used up to 300MHz.
Without the external R-C-R filter, the drive circuit has very high bandwidth & can support very high inputfrequencies (> 300MHz). For example, a transmission line transformer such as ADTL2-18 can be used(Figure 48 ).
Note that both the drive circuits have been terminated by 50 ohms near the ADC side. The termination isaccomplished by a 25 ohms resistor from each input to the 1.5V common-mode (VCM) from the device. Thisallows the analog inputs to be biased around the required common-mode voltage.
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INP
INM
VCM
1:1
15 W
0.1uF
1:1
22 pF
25 W
50 W
39 nH
39 nH
0.1 Fm
0.1 Fm
0.1 Fm
50 W
25 W
15 W
50 W
50 W
INP
INM
VCM
1:1 1:1
3.3 pF
0.1 Fm
0.1 Fm
0.1 Fm
0.1 Fm25 W
25 W
5W
5W
50 W
50 W
INP
INM
VCM
0.1 Fμ 25 Ω
25 Ω
0.1 Fμ
0.1 Fμ
T1 T2
ADS62C17
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Figure 46. Drive Circuit With Low Bandwidth (for low input frequencies)
The mismatch in the transformer parasitic capacitance (between the windings) results in degraded even-orderharmonic performance. Connecting two identical RF transformers back to back helps minimize this mismatch andgood performance is obtained for high frequency input signals. An additional termination resistor pair may berequired between the two transformers as shown in the figures. The center point of this termination is connectedto ground to improve the balance between the P and M sides. The values of the terminations between thetransformers and on the secondary side have to be chosen to get an effective 50 (in the case of 50 sourceimpedance).
Figure 47. Drive Circuit With High Bandwidth (for high input frequencies)
Figure 48. Drive circuit with very high bandwidth (> 300 MHz)
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INP
INM
VCM
1:4
5 Ω
0.1 Fμ
5 Ω
100 Ω
100 Ω
25 Ω
25 Ω
15pF72nH
Differential
input signal
Input common-mode
REFERENCE
_
+
_
+
INTERNAL
REFERENCE
INTREF
EXTREF
REFM
REFP
VCM
Internal reference
ADS62C17
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All these examples show 1:1 transformers being used with a 50 ohms source. As explained in the "Drive CircuitRequirements", this helps to present a low source impedance to absorb the sampling glitches. With a 1:4transformer, the source impedance will be 200 ohms. The higher impedance can lead to degradation inperformance, compared to the case with 1:1 transformers. For applications where only a band of frequencies areused, the drive circuit can be tuned to present a low impedance for the sampling glitches. Figure 49 shows anexample with 1:4 transformer, tuned for a band around 150MHz.
Figure 49. Drive circuit with 1:4 transformer
To ensure a low-noise common-mode reference, the VCM pin is filtered with a 0.1 µF low-inductance capacitorconnected to ground. The VCM pin is designed to directly drive the ADC inputs. The input stage of the ADCsinks a common-mode current in the order of 3.6 µA / MSPS (about 720 µA at 200 MSPS).
ADS62C17 has built-in internal references REFP and REFM, requiring no external components. Design schemesare used to linearize the converter load seen by the references; this and the on-chip integration of the requisitereference capacitors eliminates the need for external decoupling. The full-scale input range of the converter canbe controlled in the external reference mode as explained below. The internal or external reference modes canbe selected by programming the serial interface register bit < REF>.
Figure 50. Reference Section
When the device is in internal reference mode, the REFP and REFM voltages are generated internally.Common-mode voltage (1.5V nominal) is output on VCM pin, which can be used to externally bias the analoginput pins
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External reference
SNR ENHANCEMENT USING SNRBOOST
-140
-120
-100
-80
-60
-40
-20
0
Amplitude-dB
00.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
f-Frequency-MHz
CenterFrequency
=FSx0.25
Fs=200MSPS
Fin=150MHz
SNRBoostCoeff1=0x0F,
SNRBoostCoeff2=0x01,
ADS62C17
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When the device is in external reference mode, the VCM acts as a reference input pin. The voltage forced on theVCM pin is buffered and gained by 1.33 internally, generating the REFP and REFM voltages. The differentialinput voltage corresponding to full-scale is given by the following:
Full-scale differential input pp = (Voltage forced on VCM) × 1.33
In this mode, the 1.5V common-mode voltage to bias the input pins has to be generated externally.
SNRBoost technology makes it possible to overcome SNR limitations due to quantization noise. With SNRBoost,enhanced SNR can be obtained for any bandwidth (less than Nyquist or Fs/2, see Table 1 ). The SNRimprovement is achieved without affecting the default harmonic performance. SNRBoost is disabled after reset; itcan be enabled using register bit < SNRBoost Enable> or using the control pins CTRL1, 2, 3.
(While using the register bits to control SNRBoost, keep CTRL1, CTRL2, CTRL3 low. To use the CTRL pins asSNRBoost control, reset the < SNRBoost Enable> register bits).
When it is enabled, the noise floor in the spectrum acquires a typical bath-tub shape as shown in Figure 51 . Thebath-tub is centered around a specific frequency (called center frequency). The center frequency is locatedmid-way between two corner frequencies, which are specified by the SNRBoost coefficients (Register bits< SNRBoost Coeff1> and SNRBoost Coeff2>).
Table 9 shows the relation between each coefficient and its corner frequency. By choosing appropriatecoefficients, the bath-tub can be positioned over the frequency range 0 to Fs/2 (Table 10 shows someexamples). By positioning the bath-tub within the desired signal band, SNR improvement can be achieved (seeTable 1 ). Note that as the bandwidth is increased, the amount of SNR improvement reduces.
Figure 51. Specturm with SNRBoost Enabled
Table 9. Setting the Corner Frequency
SNRBoost Coefficient Value Normalized Corner Frequency SNRBoost Coefficient value Normalized Corner Frequency(f/fs) (f/fs)
7 0.080 F 0.2706 0.115 E 0.2905 0.143 D 0.3114 0.167 C 0.3333 0.189 B 0.3572 0.210 A 0.3851 0.230 9 0.4200 0.250 8 0.500
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A7 A6 A1 A0 D7 D6 D1 D0
Register address = 0x59 Register data = 0x01
SDATA
SCLK
SEN
CLKM
CLKP
N-26
Output
Data
clock
cycle 1
clock
cycle 9
clock
cycle 10
N-25
Serial register write to enable SNRBoost
10 clock cycles after the 16th SCLK
falling edge, the device starts
giving out valid SNRBoost data
Valid SNRBoost
data starts
N-1
NN+1
Analog
Input
Signal
CLOCK INPUT
ADS62C17
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Table 10. Positioning the Corner Frequency
SNRBoost Coefficient1, Normalized Corner Frequency1 SNRBoost Coefficient1, Center Frequency< SNRBoost Coeff1 > (f/fs) < SNRBoost Coeff2 >
0 0.250 0 Fs × 0.25F 0.270 1 Fs × 0.256 0.115 2 Fs × 0.165D 0.311 B Fs × 0.3359 0.420 7 Fs × 0.25
Figure 52. SNRBoost Active Delay
SNRBoost does not introduce any group delay in the input signal path. The ADC latency increases by four clockcycle (to 26 clock cycles). When it is enabled using the serial interface, the mode becomes fully active 10 inputclock cycles after the 16
th
SCLK falling edge. When it is disabled, normal data (without SNRBoost) resumes after6 clock cycle.
ADS62C17 clock inputs can be driven differentially (sine, LVPECL or LVDS) or single-ended (LVCMOS), withlittle or no difference in performance between them. The common-mode voltage of the clock inputs is set to VCMusing internal 5-k resistors as shown in Figure 53 . This allows using transformer-coupled drive circuits for sinewave clock or ac-coupling for LVPECL, LVDS clock sources (Figure 54 and Figure 55 ).
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CLKP
VCM
2 pF
Lpkg
~ 2 nH
Lpkg
~2 nH
CLKM
Clockbuffer
Ceq Ceq
Ceq~ 1 to 3 pF, equivalentinputcapacitanceofclockbuffer
C
~1pF
bond
R
~100 W
20 W
20 W
C
~1pF
bond
R
~100 W
5kW
5kW
CLKP
CLKM
0.1 Fm
0.1 Fm
Differentialsine-wave
orPECL orLVDSclockinput
ADS62C17
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Figure 53. Internal Clock Buffer
For best performance, the clock inputs have to be driven differentially, reducing susceptibility to common-modenoise. For high input frequency sampling, it is recommended to use a clock source with very low jitter. Band-passfiltering of the clock source can help reduce the effect of jitter. There is no change in performance with anon-50% duty cycle clock input.
Figure 54. Differential Clock Driving Circuit
Single-ended CMOS clock can be ac-coupled to the CLKP input, with CLKM tied to 1.5V common-mode voltage.As shown in Figure 55 , CLKM can be tied to VCM pin.
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CLKP
CLKM
VCM
0.1 Fm
0.1 Fm
CMOSclockinput
GAIN PROGRAMMABILITY
OFFSET CORRECTION
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Figure 55. Single-Ended Clock Driving Circuit
ADS62C17 includes gain settings that can be used to get improved SFDR performance (compared to 0dB gain).The gain is programmable from 0dB to 6dB (in 0.5 dB steps). For each gain setting, the analog input full-scalerange scales proportionally, as shown in Table 11 .
The SFDR improvement is achieved at the expense of SNR; for each 1dB gain step, the SNR degrades about1dB. The SNR degradation is less at high input frequencies. As a result, the gain is very useful at high inputfrequencies as the SFDR improvement is significant with marginal degradation in SNR.
So, the gain can be used to trade-off between SFDR and SNR. Note that the default gain after reset is 0 dB.
Table 11. Full-Scale Range Across Gains
Gain, dB Full-Scale, Vpp
0 2V1 1.782 1.593 1.424 1.265 1.126 1.00
ADS62C17 has an internal offset correction algorithm that estimates and corrects dc offset up to +/-10mV. Thecorrection can be enabled using the serial register bit < OFFSET CORRECTION ENABLE>. Once enabled, thealgorithm estimates the channel offset and applies the correction every clock cycle. The time constant of thecorrection loop is a function of the sampling clock frequency. The time constant can be controlled using registerbits < OFFSET CORR TIME CONSTANT> as described in Table 12 .
After the offset is estimated, the correction can be frozen by setting < OFFSET CORRECTION ENABLE> = 0.
Once frozen, the last estimated value is used for offset correction every clock cycle. The correction does notaffect the phase of the signal. Note that offset correction is disabled by default after reset.
Figure 56 shows the time response of the offset correction algorithm, after it is enabled.
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1019
1020
1021
1022
1023
1024
1025
1026
-2 0 2 4 6 8 10 12 14 16 18
Time-ms
OutputCodesm-LSB
1018
20
Offsetcorrection
disabled
Offsetcorrection
enabled
Outputdatawith
offsetcorrected
Outputdatawith
4LSBoffset
POWER DOWN
ADS62C17
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Table 12. Time Constant of Offset Correction Algorithm
< OFFSET CORR TIME Time Constant (TCCLK), Time Constant, secCONSTANT >
Number of Clock Cycles (=TC
CLK
x 1/Fs)
(1)
D3-D0
0000 256 k 1.2 ms0001 512 k 2.5 ms0010 1 M 5 ms0011 2 M 10 ms0100 4 M 20 ms0101 8 M 40 ms0110 16 M 80 ms0111 32 M 0.16 s1000 64 M 0.32 s1001 128 M 0.64 s1010 256 M 1.28 s1011 512 M 2.5 s1100 RESERVED1101 RESERVED1110 RESERVED1111 RESERVED
(1) Sampling frequency, Fs = 200 MSPS
Figure 56. Time Response of Offset Correction
ADS62C17 has three power down modes power down global, individual channel standby and individualchannel output buffer disable. These can be set using either the serial register bits or using the control pinsCTRL1 to CTRL3.
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Power Down Global
Channel Power Down (individual or both channels)
Output Buffer Disable (individual or both channels)
Input Clock Stop
POWER SUPPLY SEQUENCE
DIGITAL OUTPUT INTERFACE
DDR LVDS Interface
ADS62C17
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Table 13. Power Down Controls
POWER DOWN MODES CONFIGURE USING WAKE-UP
TIMESERIAL INTERFACE PARALLEL CONTROL
PINS
Normal operation < POWER DOWN MODES > =0000 low low low Output buffer disabled for channel B < POWER DOWN MODES > =1001 The pins do not support output bufferOutput buffer disabled for channel A < POWER DOWN MODES > =1010 disableOutput buffer disabled for channel A and B < POWER DOWN MODES > =1011 Fast (100 ns)Global power down < POWER DOWN MODES > =1100 high low low Slow (20 µs)Channel B standby < POWER DOWN MODES > =1101 high low high Fast (1 µs)Channel A standby < POWER DOWN MODES > =1110 high high low Fast (1 µs)Multiplexed (MUX) mode Output data of channel A < POWER DOWN MODES > =1111 high high high and B is multiplexed & available on DA10 to DA0pins.
In this mode, the entire chip including both the A/D converters, internal reference and the output buffers arepowered down resulting in reduced total power dissipation of about 45mW. The output buffers are in highimpedance state. The wake-up time from the global power down to data becoming valid in normal mode istypically 20 µs.
Here, each channel s A/D converter can be powered down. The internal references are active, resulting in quickwake-up time of 1 µs. The total power dissipation in standby is about 450 mW.
Each channel s output buffer can be disabled and put in high impedance state wakeup time from this mode isfast, about 100 ns.
In addition to the above, the converter enters a low-power mode when the input clock frequency falls below1MSPS. The power dissipation is about 275 mW.
During power-up, the AVDD and DRVDD supplies can come up in any sequence. The two supplies areseparated in the device.
ADS62C17 provides 11-bit data and an output clock synchronized with the data.
Two output interface options are available Double Data Rate (DDR) LVDS and parallel CMOS. They can beselected using the serial interface register bit < LVDS_CMOS> or using DFS pin in parallel configuration mode.
In this mode, the data bits and clock are output using LVDS (Low Voltage Differential Signal) levels. Two databits are multiplexed and output on each LVDS differential pair.
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CLKOUTP
CLKOUTM
DB0_P
DB0_M
DB2_P
DB2_M
DB4_P
DB4_M
DB6_P
DB6_M
DB8_P
DB8_M
DB10_P
DB10_M
OutputClock
DatabitD0
DatabitsD1,D2
DatabitsD3,D4
DatabitsD5,D6
DatabitsD7,D8
DatabitsD9,D10
ADS62C17 LVDSBuffers
11bit ADCdata
ChannelB
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Figure 57. DDR LVDS Outputs
Even data bits D0, D2, D4 are output at the falling edge of CLKOUTP and the odd data bits D1, D3, D5 areoutput at the rising edge of CLKOUTP. Both the rising and falling edges of CLKOUTP have to be used to captureall the data bits (Figure 58 ).
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SAMPLE NSAMPLE N
CLKOUTMCLKOUTM
CLKOUTPCLKOUTP
DA0, DB0DA0, DB0
SAMPLE N+1SAMPLE N+1
DA2, DB2DA2, DB2
DA4,DB4DA4,DB4
DA6,DB6DA6,DB6
DA8,DB8DA8,DB8
DA10,DB10DA10,DB10
D0
D1 D2
D3 D4
D5 D6
D7 D8
D9 D10
D0
D1 D2
D3 D4
D5 D6
D7 D8
D9 D10
00
LVDS Buffer
ADS62C17
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Figure 58. DDR LVDS Interface
The equivalent circuit of each LVDS output buffer is shown in Figure 59 . The buffer is designed to present anoutput impedance of 100 (Rout). The differential outputs can be terminated at the receive end by a 100 termination.
The buffer output impedance behaves like a source-side series termination. By absorbing reflections from thereceiver end, it helps to improve signal integrity. Note that this internal termination cannot be disabled and itsvalue cannot be changed.
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Whenthe “High” switchesareclosed , OUTP = 1.375 V, OUTM = 1.025 V
Whenthe “Low” switchesareclosed , OUTP = 1.025 V, OUTM = 1.375 V
Switchimpedanceis
nominally 50 W(+/- 10%)
Whenthe “High” (or “Low”) switchesareclosed, Rout = 100 W
1.2 V
+ 0.35 V
- 0.35 V
OUTP
OUTM
Rout
ADS62C18
Low
High
Low High
Parallel CMOS Interface
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Figure 59. LVDS Buffer Equivalent Circuit
In the CMOS mode, each data bit is output on separate pin as CMOS voltage level, every clock cycle. The risingedge of the output clock CLKOUT can be used to latch data in the receiver (for sampling frequencies up to150 MSPS).
Up to 150MSPS, the setup and hold timings of the output data with respect to CLKOUT are specified. It isrecommended to minimize the load capacitance seen by data and clock output pins by using short traces to thereceiver. Also, match the output data and clock traces to minimize the skew between them.
For sampling frequencies above 150 MSPS, it is recommended to use an external clock to capture data. Thedelay from input clock to output data and the data valid times are specified for the higher sampling frequencies.These timings can be used to delay the input clock appropriately and use it to capture the data.
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DA0
DA1
DA2
DA8
Pins
DA9
DA10
CLKOUT
11 bit ADC data
Channel A
SDOUT
11 bit ADC data
Channel B
DB0
DB1
DB2
DB8
DB9
DB10
CMOS Interface Power Dissipation
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Figure 60. Parallel CMOS Outputs
With CMOS outputs, the DRVDD current scales with the sampling frequency and the load capacitance on everyoutput pin. The maximum DRVDD current occurs when each output bit toggles between 0 and 1 every clockcycle. In actual applications, this condition is unlikely to occur. The actual DRVDD current would be determinedby the average number of output bits switching, which is a function of the sampling frequency and the nature ofthe analog input signal.
Digital current due to CMOS output switching = C
L
× DRVDD × (N × F
AVG
),
where C
L
= load capacitance, N × F
AVG
= average number of output bits switching.
Figure 38 shows the current with various load capacitances across sampling frequencies at 2 MHz analog inputfrequency.
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Output Data Format
BOARD DESIGN CONSIDERATIONS
MIGRATION FROM ADS62C15 TO ADS62C17
ADS62C17
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Two output data formats are supported 2s complement and offset binary. They can be selected using the serialinterface register bit < DATA FORMAT> or controlling the DFS pin in parallel configuration mode.
In the event of an input voltage overdrive, the digital outputs go to the appropriate full scale level. For a positiveoverdrive, the output code is 0x7FF in offset binary output format, and 0x3FF in 2s complement output format.For a negative input overdrive, the output code is 0x000 in offset binary output format and 0x400 in 2scomplement output format.
Grounding
A single ground plane is sufficient to give good performance, provided the analog, digital, and clock sections ofthe board are cleanly partitioned. See the EVM User Guide (SLAU237A) for details on layout and grounding.
Supply Decoupling
As ADS62C17 already includes internal decoupling, minimal external decoupling can be used without loss inperformance. Note that decoupling capacitors can help filter external power supply noise, so the optimumnumber of capacitors would depend on the actual application. The decoupling capacitors should be placed veryclose to the converter supply pins.
Exposed PadIn addition to providing a path for heat dissipation, the pad is also electrically connected to digital groundinternally. So, it is necessary to solder the exposed pad to the ground plane for best thermal and electricalperformance. For detailed information, see application notes QFN Layout Guidelines (SLOA122 ) and QFN/SON.
PCB Attachment (SLUA271 ).
While migrating from the C15 to C17, note the following differences between the two devices.ADS62C15 ADS62C17
Pinout
Pin 22 is AGND Pin 22 is NCPin 64 is DRGND Pin 64 is SDOUT (Serial readout pin)
Supply
AVDD is 3.3V No changeDRVDD is 1.8V to 3.3V (for CMOS interface) and is DRVDD is 1.8V (for both CMOS and LVDS3.3V (for LVDS interface) interfaces)
Serial Interface
Protocol: 8 bit register address & 8 bit register data No change in protocolSerial register map is completely different
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DEFINITION OF SPECIFICATIONS
10 S
N
P
SNR = 10Log P
(3)
10 S
N D
P
SINAD = 10Log P + P
(4)
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Analog Bandwidth The analog input frequency at which the power of the fundamental is reduced by 3 dB withrespect to the low frequency value.
Aperture Delay The delay in time between the rising edge of the input sampling clock and the actual time atwhich the sampling occurs. This delay will be different across channels. The maximum variation is specified asaperture delay variation (channel-channel).
Aperture Uncertainty (Jitter) The sample-to-sample variation in aperture delay.
Clock Pulse Width/Duty Cycle The duty cycle of a clock signal is the ratio of the time the clock signal remainsat a logic high (clock pulse width) to the period of the clock signal. Duty cycle is typically expressed as apercentage. A perfect differential sine-wave clock results in a 50% duty cycle.
Maximum Conversion Rate The maximum sampling rate at which certified operation is given. All parametrictesting is performed at this sampling rate unless otherwise noted.
Minimum Conversion Rate The minimum sampling rate at which the ADC functions.
Differential Nonlinearity (DNL) An ideal ADC exhibits code transitions at analog input values spaced exactly1 LSB apart. The DNL is the deviation of any single step from this ideal value, measured in units of LSBs.
Integral Nonlinearity (INL) The INL is the deviation of the ADC's transfer function from a best fit linedetermined by a least squares curve fit of that transfer function, measured in units of LSBs.
Gain Error Gain error is the deviation of the ADC's actual input full-scale range from its ideal value. The gainerror is given as a percentage of the ideal input full-scale range. Gain error has two components: error due toreference inaccuracy and error due to the channel. Both these errors are specified independently as E
GREF
andE
GCHAN
.
To a first order approximation, the total gain error will be E
TOTAL
~ E
GREF
+ E
GCHAN
.
For example, if E
TOTAL
= ± 0.5%, the full-scale input varies from (1-0.5/100) x FS
ideal
to (1 + 0.5/100) x FS
ideal
.
Offset Error The offset error is the difference, given in number of LSBs, between the ADC's actual averageidle channel output code and the ideal average idle channel output code. This quantity is often mapped into mV.
Temperature Drift The temperature drift coefficient (with respect to gain error and offset error) specifies thechange per degree Celsius of the parameter from T
MIN
to T
MAX
. It is calculated by dividing the maximum deviationof the parameter across the T
MIN
to T
MAX
range by the difference T
MAX
T
MIN
.
Signal-to-Noise Ratio SNR is the ratio of the power of the fundamental (PS) to the noise floor power (PN),excluding the power at DC and the first nine harmonics.
SNR is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as thereference, or dBFS (dB to full scale) when the power of the fundamental is extrapolated to the converter sfull-scale range.
Signal-to-Noise and Distortion (SINAD) SINAD is the ratio of the power of the fundamental (P
S
) to the powerof all the other spectral components including noise (P
N
) and distortion (P
D
), but excluding dc.
SINAD is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as thereference, or dBFS (dB to full scale) when the power of the fundamental is extrapolated to the converter'sfull-scale range.
Effective Number of Bits (ENOB) The ENOB is a measure of the converter performance as compared to thetheoretical limit based on quantization noise.
Copyright © 2009, Texas Instruments Incorporated Submit Documentation Feedback 59
Product Folder Link(s): ADS62C17
SINAD 1.76
ENOB =
6.02
-
(5)
10 S
N
P
THD = 10Log P
(6)
(ExpressedindBc)
DVSUP
DVOUT
10
PSRR=20Log
(7)
(ExpressedindBc)
DVCM
DVOUT
10
CMRR=20Log
(8)
ADS62C17
SLAS631 APRIL 2009 .....................................................................................................................................................................................................
www.ti.com
Total Harmonic Distortion (THD) THD is the ratio of the power of the fundamental (P
S
) to the power of thefirst nine harmonics (PD).
THD is typically given in units of dBc (dB to carrier).
Spurious-Free Dynamic Range (SFDR) The ratio of the power of the fundamental to the highest otherspectral component (either spur or harmonic). SFDR is typically given in units of dBc (dB to carrier).
Two-Tone Intermodulation Distortion IMD3 is the ratio of the power of the fundamental (at frequencies f1and f2) to the power of the worst spectral component at either frequency 2f1 f2 or 2f2 f1. IMD3 is either given inunits of dBc (dB to carrier) when the absolute power of the fundamental is used as the reference, or dBFS (dB tofull scale) when the power of the fundamental is extrapolated to the converter s full-scale range.
DC Power Supply Rejection Ratio (DC PSRR) The DC PSSR is the ratio of the change in offset error to achange in analog supply voltage. The DC PSRR is typically given in units of mV/V.
AC Power Supply Rejection Ratio (AC PSRR) AC PSRR is the measure of rejection of variations in thesupply voltage by the ADC. If ΔV
SUP
is the change in supply voltage and ΔVout is the resultant change of theADC output code (referred to the input), then
Voltage Overload Recovery The number of clock cycles taken to recover to less than 1% error after anoverload on the analog inputs. This is tested by separately applying a sine wave signal with 6dB positive andnegative overload. The deviation of the first few samples after the overload (from their expected values) is noted.
Common Mode Rejection Ratio (CMRR) CMRR is the measure of rejection of variation in the analog inputcommon-mode by the ADC. If ΔVcm_in is the change in the common-mode voltage of the input pins and ΔV
OUTis the resultant change of the ADC output code (referred to the input), then
Cross-Talk (only for multi-channel ADC) This is a measure of the internal coupling of a signal from adjacentchannel into the channel of interest. It is specified separately for coupling from the immediate neighboringchannel (near-channel) and for coupling from channel across the package (far-channel). It is usually measuredby applying a full-scale signal in the adjacent channel. Cross-talk is the ratio of the power of the coupling signal(as measured at the output of the channel of interest) to the power of the signal applied at the adjacent channelinput. It is typically expressed in dBc.
60 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated
Product Folder Link(s): ADS62C17
PACKAGING INFORMATION
Orderable Device Status (1) Package
Type Package
Drawing Pins Package
Qty Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
ADS62C17IRGC25 PREVIEW VQFN RGC 64 25 TBD Call TI Call TI
ADS62C17IRGCR ACTIVE VQFN RGC 64 2000 Green (RoHS &
no Sb/Br) CU NIPDAU Level-3-260C-168 HR
ADS62C17IRGCT ACTIVE VQFN RGC 64 250 Green (RoHS &
no Sb/Br) CU NIPDAU Level-3-260C-168 HR
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
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incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com 10-Nov-2009
Addendum-Page 1
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0 (mm) B0 (mm) K0 (mm) P1
(mm) W
(mm) Pin1
Quadrant
ADS62C17IRGCR VQFN RGC 64 2000 330.0 16.4 9.3 9.3 1.5 12.0 16.0 Q2
ADS62C17IRGCT VQFN RGC 64 250 330.0 16.4 9.3 9.3 1.5 12.0 16.0 Q2
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Apr-2009
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
ADS62C17IRGCR VQFN RGC 64 2000 333.2 345.9 28.6
ADS62C17IRGCT VQFN RGC 64 250 333.2 345.9 28.6
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Apr-2009
Pack Materials-Page 2
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