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MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
19-5252; Rev 1; 6/11
Typical Operating Circuit appears at end of data sheet.
General Description
The MAX14979E is optimized for high-speed differential
switching applications. The device is ideal for low-volt-
age differential signal (LVDS) and low-voltage positive
emitter-coupled logic (LVPECL) switching applications.
The MAX14979E provides enhanced electrostatic dis-
charge (ESD) protection up to Q15kV and excellent high-
frequency response, making this device especially use-
ful for interfaces that must go to an outside connection.
The MAX14979E provides extremely low capacitance
(CON) as well as low resistance (RON) for low-insertion
loss and bandwidth up to 650MHz (1.3Gbps). In addi-
tion to the four pairs of double-pole/double-throw (DPDT)
switches, the MAX14979E provides low-frequency (up
to 50MHz) and AUX switching that can be used for LED
lighting or other applications.
The MAX14979E is available in a space-saving 36-pin
TQFN package and operates over the standard -40NC to
+85NC temperature range.
Applications
Notebook Computers
Switch LVDS to Graphics Panels
LVDS and LVPECL Switching
Ordering Information
Features
S ±15kV ESD Protected per MIL-STD-883, Method
3015
S Single +3.0V to +3.6V Power-Supply Voltage
S Low On-Resistance (RON): 4I (typ), 6.5I (max)
S Low On-Capacitance (CON): 8pF (typ)
S -23dB Return Loss (100MHz)
S -3dB Bandwidth: 650MHz
S Built-In AUX Switches for Switching Indicators
S Low 450µA (max) Quiescent Current
S Bidirectional 8 to 16 Multiplexer/Demultiplexer
S Space-Saving, Lead-Free, 36-Pin, 6mm x 6mm
TQFN Package
Eye Diagram
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad. 500ps/div
100mV/div
f = 300MHz
PART TEMP RANGE PIN-PACKAGE
MAX14979EETX+ -40NC to +85NC36 TQFN-EP*
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
2
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
(Voltages referenced to GND.)
V+ .........................................................................-0.3V to +4.0V
All Other Pins ...............................................-0.3V to (V+ + 0.3V)
Continuous Current (COM_ _ to NC_ _/NO_ _) ............ Q120mA
Continuous Current (AUX0_ to AUX1_/AUX2_) ............... Q40mA
Peak Current (COM_ _ to NC_ _/NO_ _)
(pulsed at 1ms, 10% duty cycle) ............................... Q240mA
Current into Any Other Pin .............................................. Q20mA
Continuous Power Dissipation (TA = +70NC)
36-Pin TQFN (derate 35.7mW/NC above +70NC) .......2.85mW
Operating Temperature Range ........................ -40NC to +85NC
Junction Temperature .................................................. +150NC
Storage Temperature Range ......................... -65NC to +150NC
Lead Temperature (soldering 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
ELECTRICAL CHARACTERISTICS
(V+ = +3.0V to +3.6V, TA = TJ = TMIN to TMAX, unless otherwise noted. Typical values are at V+ = +3.3V, TA = +25NC.) (Note 2)
ABSOLUTE MAXIMUM RATINGS
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
TQFN
Junction-to-Ambient Thermal Resistance (BJA) ............8NC/W
Junction-to-Case Thermal Resistance (BJC) .................1NC/W
PACKAGE THERMAL CHARACTERISTICS (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
POWER SUPPLIES
Operating Power-Supply Range V+ +3.0 +3.6 V
ANALOG SWITCH
On-Resistance RON V+ = 3V, ICOM_ _ = -40mA,
VCOM_ _ = 0V, 1.5V, 3V
TA = +25NC4 5.5 I
TMIN to TMAX 6.5
On-Resistance AUX Switches RONAUX V+ = 3V, IAUX0_ = -40mA, VAUX0_ = 0V,
1.5V, 3V 40 I
On-Resistance Match
Between Channels DRON V+ = 3V, ICOM_ _ = -40mA,
VCOM_ _ = 0V, 3V (Note 3)
TA = +25NC0.5 1.5 I
TMIN to TMAX 2
On-Resistance Flatness RFLAT(ON) V+ = 3V, ICOM_ _ = -40mA,
VCOM_ _ = 0V, 1.5V 0.01 I
Off-Leakage Current ILCOM_
_(OFF)
V+ = 3.6V, VCOM_ _ = 0.3V, 3.3V;
VNC_ _ or VNO_ _ = 3.3V, 0.3V -1 +1 FA
On-Leakage Current ILCOM_
_(ON)
V+ = 3.6V, VCOM_ _ = 0.3V, 3.3V; VNC_ _
or VNO_ _ = 3.3V, 0.3V or unconnected -1 +1 FA
SWITCH AC PERFORMANCE
Insertion Loss ILOS RS = RL = 50I, unbalanced, f = 1MHz,
(Note 3) 0.6 dB
Return Loss RLOS f = 100MHz -23 dB
Crosstalk
VCT1 Any switch to any switch;
RS = RL = 50I,
unbalanced, Figure 1
f = 25MHz -50
dB
VCT2 f = 125MHz -26
SWITCH AC CHARACTERISTICS
-3dB Bandwidth BW RS = RL = 50I, unbalanced 650 MHz
Off-Capacitance COFF f = 1MHz, COM_ _ 3.5 pF
On-Capacitance CON f = 1MHz, COM_ _ 8 pF
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
3
ELECTRICAL CHARACTERISTICS (continued)
(V+ = +3.0V to +3.6V, TA = TJ = TMIN to TMAX, unless otherwise noted. Typical values are at V+ = +3.3V, TA = +25NC.) (Note 2)
Note 2: Specifications at TA = -40NC are guaranteed by design.
Note 3: Guaranteed by design.
Figure 1. Single-Ended Bandwidth, Crosstalk, and Off-Isolation
R15
49.9Ω
NETWORK
ANALYZER
NETWORK
ANALYZER
NETWORK
ANALYZER
NETWORK
ANALYZER
SINGLE-ENDED BANDWIDTH
50Ω TRACE
SINGLE-ENDED CROSSTALK
50Ω TRACE
SINGLE-ENDED OFF-ISOLATION
50Ω TRACE
50Ω TRACE
COM0+
36
COM1+
2
COM1-
3
COM2+
7
NC2+
22
NC1-
25
NC1+
26
NC0+
31 50Ω TRACE NETWORK
ANALYZER
NETWORK
ANALYZER
50Ω TRACE
R14
49.9Ω
R13
49.9Ω
MAX14979E
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Turn-On Time tON VCOM_ _ = 1V, RL = 100I, Figure 2 50 ns
Turn-Off Time tOFF VCOM_ _ = 1V, RL = 100I, Figure 2 50 ns
Propagation Delay tPLH, tPHL RS = RL = 50I, unbalanced, Figure 3 0.1 ns
Output Skew Between Ports tSK(o) Skew between any two ports, Figure 4 0.01 ns
SWITCH LOGIC
Input-Voltage Low VIL V+ = 3.0V 0.8 V
Input-Voltage High VIH V+ = 3.6V 2.0 V
Input-Logic Hysteresis VHYST V+ = 3.3V 100 mV
Input Leakage Current ISEL V+ = 3.6V, VSEL = 0V or V+ -5 +5 FA
Quiescent Supply Current I+ V+ = 3.6V, VSEL = 0V or V+ 280 450 FA
ESD PROTECTION
ESD Protection COM_ _, NC_ _, NO_ _
HBM (spec MIL-STD-883, Method 3015) Q15 kV
All Other Pins HBM (spec MIL-STD-883, Method 3015) Q2kV
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
4
Figure 2. Turn-On and Turn-Off Times Figure 3. Propagation Delay Times
Figure 4. Output Skew
SEL
50%
50%
tOFF
50%
50% 50%
50%
VIH
VIL
0V
0V
NC_ _
NO_ _
tON
tOFF
tON
COM_ _
NC_ _
NO_ _
VH
2.0V
2.0V
1.0V
3.0V
VL
tPLH tPHL
THE MAX14979E SWITCHES ARE FULLY BIDIRECTIONAL.
PULSE SKEW = tSK(o) = |tPHL - tPLH|
2.0V
3.0V
1.0V
THE MAX14979E SWITCHES ARE FULLY BIDIRECTIONAL.
VOH
VOL
2.0V
COM_ _
NC_ _
NO_ _
NC_ _
NO_ _
OUTPUT SKEW = tSK(o) = |tPHL - tPHL|
VOH
VOL
2.0V
tPLH tPHL
tPLH tPHL
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
5
Typical Operating Characteristics
(V+ = 3.3V, TA = +25NC, unless otherwise noted.)
SINGLE-ENDED INSERTION LOSS
vs. FREQUENCY
MAX14979E toc05
FREQUENCY (MHz)
INSERTION LOSS (dB)
10010
-7
-6
-5
-4
-3
-2
-1
0
-8
1 1000
200
220
240
260
280
300
320
340
-40 -15 10 35 60 85
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
MAX14979E toc04
TEMPERATURE (°C)
QUIESCENT SUPPLY CURRENT (µA)
V+ = 3.6V
0
12
8
4
16
20
24
28
32
36
40
-40 10-15 35 60 85
LEAKAGE CURRENT vs. TEMPERATURE
MAX14979E toc03
TEMPERATURE (°C)
LEAKAGE CURRENT (pA)
IL(ON)
IL(OFF)
0
8
10
12
14
6
2
4
16
18
22
20
24
0 1.0
0.5 1.5 2.0 2.5 3.0
AUX_ ON-RESISTANCE vs. VAUX_
MAX14979E toc02
VAUX_ (V)
RONAUX (Ω)
TA = +85°C
TA = +25°C
TA = -40°C
0
2
1
4
3
5
6
0 1.0 1.50.5 2.0 2.5 3.0
ON-RESISTANCE vs. VCOM_ _
MAX14979E toc01
VCOM_ _ (V)
RON (Ω)
TA = +85°C
TA = +25°C TA = -40°C
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
6
Pin Configuration
Pin Description
SEL
NC1+
NO1+
NO1-
NO2+
NO2-
NC2+
NC2-
NC1-COM1-
AUX0A
AUX1A
COM2+
COM2-
COM3+
COM0- 1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
28
29
30
31
32
33
34
35
36
27
26
25
24
23
22
21
20
19
AUX2B
AUX1B
AUX0B
COM3-
*CONNECT EP TO GND.
NO3-
NO3+
NC3-
NC3+
NO0+
NC0-
NC0+
AUX2
AUX1
AUX0
+
V+
COM0+
*EP
NO0-
TQFN
TOP VIEW
AUX2A
GND
COM1+
MAX14979E
PIN NAME FUNCTION
1 COM0- Common LVDS Differential Terminal for Switch 0
2 COM1+ Common LVDS Differential Terminal for Switch 1
3 COM1- Common LVDS Differential Terminal for Switch 1
4 AUX0A AUX0A Input
5 AUX1A AUX1A Output. Drive SEL low (SEL = 0) to connect AUX0A to AUX1A.
6 AUX2A AUX2A Output. Drive SEL high (SEL = 1) to connect AUX0A to AUX2A.
7 COM2+ Common LVDS Differential Terminal for Switch 2
8 COM2- Common LVDS Differential Terminal for Switch 2
9 COM3+ Common LVDS Differential Terminal for Switch 3
10 COM3- Common LVDS Differential Terminal for Switch 3
11 GND Ground
12 AUX0B AUX0B Input
13 AUX1B AUX1B Output. Drive SEL low (SEL = 0) to connect AUX0B to AUX1B.
14 AUX2B AUX2B Output. Drive SEL high (SEL = 1) to connect AUX0B to AUX2B.
15 NO3- Normally Open LVDS Differential Terminal for Switch 3
16 NO3+ Normally Open LVDS Differential Terminal for Switch 3
17 NC3- Normally Closed LVDS Differential Terminal for Switch 3
18 NC3+ Normally Closed LVDS Differential Terminal for Switch 3
19 NO2- Normally Open LVDS Differential Terminal for Switch 2
20 NO2+ Normally Open LVDS Differential Terminal for Switch 2
21 NC2- Normally Closed LVDS Differential Terminal for Switch 2
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
7
Detailed Description
The MAX14979E is a high-speed analog switch targeted
at LVDS and other low-voltage switching up to 600MHz.
In a typical application, the MAX14979E switches two
sets of LVDS sources to a laptop LVDS panel. For extra
security, the MAX14979E is protected against Q15kV
ESD shocks. See the Functional Diagram.
With its low resistance and capacitance, as well as high-
ESD protection, the MAX14979E can be used to switch
most low-voltage differential signals, such as LVDS and
LVPECL, as long as the signals do not exceed the maxi-
mum ratings of the device.
The MAX14979E switches provide low capacitance and
on-resistance to meet low insertion loss and return-loss
specifications. The MAX14979E has three additional
AUX switches.
Digital Control Inputs
The MAX14979E provides a single digital control SEL.
SEL controls the switches as well as the AUX switches,
as shown in Table 1.
Analog-Signal Levels
The on-resistance of the MAX14979E is very low and
stable as the analog input signals are swept from ground
to V+ (see the Typical Operating Characteristics). The
switches are bidirectional, allowing COM_ _ and NC_ _/
NO_ _ to be configured as either inputs or outputs.
ESD Protection
The MAX14979E is characterized using the HBM for
Q15kV of ESD protection. Figure 5 shows the HBM. This
model consists of a 100pF capacitor charged to the ESD
voltage of interest, which is then discharged into the test
device through a 1.5kI resistor. All signal and control
pins are ESD protected to Q15kV HBM.
Pin Description (continued)
Figure 5. Human Body ESD Test Model (MIL-STD-883, Method
3015)
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RC
1MΩ
RD
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
PIN NAME FUNCTION
22 NC2+ Normally Closed LVDS Differential Terminal for Switch 2
23 NO1- Normally Open LVDS Differential Terminal for Switch 1
24 NO1+ Normally Open LVDS Differential Terminal for Switch 1
25 NC1- Normally Closed LVDS Differential Terminal for Switch 1
26 NC1+ Normally Closed LVDS Differential Terminal for Switch 1
27 SEL Select Input. SEL selects switch connection. See Table1.
28 NO0- Normally Open LVDS Differential Terminal for Switch 0
29 NO0+ Normally Open LVDS Differential Terminal for Switch 0
30 NC0- Normally Closed LVDS Differential Terminal for Switch 0
31 NC0+ Normally Closed LVDS Differential Terminal for Switch 0
32 AUX2 AUX2 Output. Drive SEL high (SEL = 1) to connect AUX0 to AUX2.
33 AUX1 AUX1 Output. Drive SEL low (SEL = 0) to connect AUX0 to AUX1.
34 AUX0 AUX0 Input
35 V+ Positive-Supply Voltage Input. Bypass V+ to GND with a 0.1FF ceramic capacitor.
36 COM0+ Common LVDS Differential Terminal for Switch 0
— EP Exposed Pad. Connect exposed pad to GND or leave it unconnected.
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
8
Applications Information
Typical Operating Circuit
The Typical Operating Circuit shows the MAX14979E in
a dual graphics application.
Power-Supply Sequencing and
Overvoltage Protection
Caution: Do not exceed the absolute maximum ratings.
Stresses beyond the listed ratings may cause permanent
damage to the device.
Proper power-supply sequencing is recommended for
all CMOS devices. Always apply V+ before applying
analog signals, especially if the analog signal is not cur-
rent limited.
Layout
High-speed switches require proper layout and design
procedures for optimum performance. Keep design-
controlled-impedance PCB traces as short as possible.
Ensure that bypass capacitors are as close as possible
to the device. Use large ground planes where possible.
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
Functional Diagram
Table 1. Truth Table
MAX14979E
NC0+
COM0+
NC0-
COM0-
NO0-
NO0+
NC1+
COM1+
NC1-
COM1-
NO1-
NO1+
NC2+
COM2+
NC2-
COM2-
NO2-
NO2+
NC3+
COM3+
NC3-
COM3-
NO3-
NO3+
AUX1A
AUX0A
AUX2A
AUX1B
AUX1
AUX0B
AUX2B
AUX0
SEL
AUX2
SEL CONNECTION
0 COM_ _ to NC_ _, AUX0_ to AUX1_
1 COM_ _ to NO_ _, AUX0_ to AUX2_
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
36 TQFN-EP T3666+3 21-0141 90-0050
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
9
Typical Operating Circuit
MAX14979E
COM0+
COM0-
COM1+
COM1-
COM2+
COM2-
SEL
CONTROL
NO0+
NO0-
NO1+
NO1-
NO2+
NO2-
NO3+
NO3-
COM3+
COM3-
NC0+
NC0-
NC1+
NC1-
NC2+
NC2-
NC3+
NC3-
LVDS_+
LVDS_-
CLOCK_-
CLOCK_+
LVDS_-
LVDS_+
LVDS_-
LVDS_+
LVDS_+
LVDS_-
CLOCK_-
CLOCK_+
LVDS_-
LVDS_+
LVDS_-
LVDS_+
INTERNAL
GRAPHICS
LVDS
LCD
PANEL
MAX14979E
COM0+
COM0-
COM1+
COM1-
COM2+
COM2-
SEL
CONTROL
NO0+
NO0-
NO1+
NO1-
NO2+
NO2-
NO3+
NO3-
COM3+
COM3-
NC0+
NC0-
NC1+
NC1-
NC2+
NC2-
NC3+
NC3-
LVDS_+
LVDS_-
CLOCK_-
CLOCK_+
LVDS_-
LVDS_+
LVDS_-
LVDS_+
LVDS_+
LVDS_-
CLOCK_-
CLOCK_+
LVDS_-
LVDS_+
LVDS_-
LVDS_+
SVDO TO LVDS
NOTE: THE MAX14979E HAS THREE SPDT AUXILLIARY SWITCHES (AUX) THAT CAN BE USED FOR OTHER SWITCHING SUCH AS LEDs AND I2C. THESE ARE NOT SHOWN IN THE DIAGRAM.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
10 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 4/10 Initial release —
1 6/11 Updated Package Thermal Characteristics style; corrected Pin Configuration and
Pin Description for AUX1_ and AUX2_ pins 2, 6
