Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier DESCRIPTION NE5517/5517A PIN CONFIGURATION The NE5517 contains two current-controlled transconductance amplifiers, each with a differential input and push-pull output. The NE5517 offers significant design and performance advantages over similar devices for all types of programmable gain applications. Circuit performance is enhanced through the use of linearizing diodes at the inputs which enable a 10dB signal-to-noise improvement referenced to 0.5% THD. The NE5517 is suited for a wide variety of industrial and consumer applications and is recommended as the preferred circuit in the Dolby* HX (Headroom Extension) system. N, D Packages IABCa 1 16 IABCb Da 2 15 Db 3 14 +INb -INa 4 13 -INb VOa 5 12 VOb V- 6 11 V+ 7 10 INBUFFERb VOBUFFERa 8 9 VOBUFFERb +INa INBUFFERa Constant impedance buffers on the chip allow general use of the NE5517. These buffers are made of Darlington transistor and a biasing network which changes bias current in dependence of IABC. Top View Therefore, changes of output offset voltages are almost eliminated. This is an advantage of the NE5517 compared to LM13600. With the LM13600, a burst in the bias current IABC guides to an audible offset voltage change at the output. With the constant impedance buffers of the NE5517 this effect can be avoided and makes this circuit preferable for high quality audio applications. APPLICATIONS * Multiplexers * Timers * Electronic music synthesizers * Dolby HX Systems * Current-controlled amplifiers, filters * Current-controlled oscillators, impedances FEATURES * Constant impedance buffers * VBE of buffer is constant with amplifier IBIAS change * Pin compatible with LM13600 * Excellent matching between amplifiers * Linearizing diodes * High output signal-to-noise ratio Dolby is a registered trademark of Dolby Laboratories Inc., San Francisco, Calif. PIN DESIGNATION PIN NO. SYMBOL 1 IABC 2 D 3 +IN Non-inverting input A 4 -IN Inverting input A 5 VO Output A 6 V- Negative supply 7 INBUFFER Buffer input A 8 VOBUFFER Buffer output A 9 VOBUFFER Buffer output B 10 INBUFFER Buffer input B 11 V+ Positive supply 12 VO Output B 13 -IN Inverting input B 14 +IN Non-inverting input B 15 D 16 IABC August 31, 1994 NAME AND FUNCTION Amplifier bias input A Diode bias A Diode bias B Amplifier bias input B 92 853-0887 13721 Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A CIRCUIT SCHEMATIC V+ 11 D4 D6 Q12 Q14 Q6 Q13 7,10 Q10 8,9 Q7 Q11 2,15 VOUTPUT D3 D2 Q4 -INPUT 4,13 Q5 5,12 +INPUT 3,14 Q15 1,16 AMP BIAS INPUT Q16 Q3 Q2 D7 Q9 R1 Q1 D8 Q8 D1 D5 V- 6 CONNECTION DIAGRAM B AMP BIAS INPUT B DIODE BIAS B INPUT (+) B INPUT (-) 16 15 14 13 B OUTPUT V+ (1) B BUFFER INPUT B BUFFER OUTPUT 12 11 10 9 5 6 7 8 - B + + A - 1 AMP BIAS INPUT A 2 DIODE BIAS A 3 4 INPUT (+) A INPUT (-) A OUTPUT A NOTE: 1. V+ of output buffers and amplifiers are internally connected. August 31, 1994 93 V- BUFFER INPUT A BUFFER OUTPUT A Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A ORDERING INFORMATION DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG # 16-Pin Plastic Dual In-Line Package (DIP) 0 to +70C NE5517N 0406C 16-Pin Plastic Dual In-Line Package (DIP) 0 to +70C NE5517AN 0406C 16-Pin Small Outline (SO) Package 0 to +70C NE5517D 0005D ABSOLUTE MAXIMUM RATINGS SYMBOL PARAMETER RATING UNIT NE5517 36 VDC or 18 V NE5517A 44 VDC or 22 V NE5517N, NE5517AN 1500 mW NE5517D 1125 mW Supply voltage1 VS PD Power dissipation, TA=25C (still air)2 VIN Differential input voltage 5 V ID Diode bias current 2 mA IABC Amplifier bias current 2 mA ISC Output short-circuit duration IOUT Buffer output current3 TA Operating temperature range VDC DC input voltage TSTG Storage temperature range TSOLD Lead soldering temperature (10sec max) Indefinite NE5517N, NE5517AN 20 mA 0C to +70 C +VS to -VS -65C to +150C C 300 C NOTES: 1. For selections to a supply voltage above 22V, contact factory 2. The following derating factors should be applied above 25C N package at 12.0mW/C D package at 9.0mW/C 3. Buffer output current should be limited so as to not exceed package dissipation. DC ELECTRICAL CHARACTERISTICS1 SYMBOL VOS PARAMETER Input offset voltage 0.4 5 7 VOS including diodes Diode bias current (ID)=500A 0.5 5A IABC 500A 0.1 IOS/T Input bias current IB/T Forward transconductance 0.1 Avg. TC of input offset current 0.001 Over temperature range 0.4 1 Avg. TC of input current Over temperature range August 31, 1994 5 Max 0.4 2 mV 5 mV 9600 0.5 0.6 5 8 94 350 300 5 500 2 mV 0.1 3 mV 0.1 0.6 0.4 1 7700 4000 9600 5 7 650 5 500 A A A/C 12000 mho mho 7 650 A A A 0.3 3 350 300 A A/C 0.01 13000 mV V/C 0.001 0.3 RL=0, IABC=5A RL=0, IABC=500A RL=0, 2 7 5 UNIT Typ 0.3 0.01 6700 5400 gM tracking Peak output current Min Over temperature range Avg. TC of input offset voltage Input offset current IOUT Max VOS/T Input offset change NE5517A Typ 0.3 IOS gM NE5517 Min IABC 5A VOS IBIAS TEST CONDITIONS dB Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A DC ELECTRICAL CHARACTERISTICS1 (continued) SYMBOL VOUT PARAMETER NE5517 Min Typ RL=, 5AIABC500A +12 +14.2 RL=, 5AIABC500A -12 -14.4 NE5517A Max Min Typ +12 +14.2 -12 -14.4 Max UNIT Peak output voltage Positive Negative ICC TEST CONDITIONS Supply current V V IABC=500A, both channels 2.6 4 2.6 4 mA Positive VOS/ V+ 20 150 20 150 V/V Negative VOS/ V- 20 150 20 150 V/V VOS sensitivity CMRR Common-mode rejection ration Common-mode range Crosstalk IIN Differential input current Leakage current RIN Input resistance BW Open-loop bandwidth SR Slew rate INBUFFER VO- 80 110 80 110 dB 12 13.5 12 13.5 V 100 dB Referred to input2 20Hz<f<20kHz 100 IABC=0, input=4V 0.02 100 0.02 10 IABC=0 (Refer to test circuit) 0.2 100 0.2 5 10 26 10 k MHz 2 2 50 50 Buff. input current 5 0.4 Peak buffer output voltage 5 10 nA 26 Unity gain compensated 5 nA 0.4 V/s 5 10 A V BUFFER VBE of buffer Refer to Buffer VBE test3 circuit 0.5 5 0.5 5 mV NOTES: 1. These specifications apply for VS=15V, TA=25C, amplifier bias current (IABC)=500A, Pins 2 and 15 open unless otherwise specified. The inputs to the buffers are grounded and outputs are open. 2. These specifications apply for VS=15V, IABC=500A, ROUT=5k connected from the buffer output to -VS and the input of the buffer is connected to the transconductance amplifier output. 3. VS=15, ROUT=5k connected from Buffer output to -VS and 5A IABC 500A. August 31, 1994 95 Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A TYPICAL PERFORMANCE CHARACTERISTICS VS = 15V 3 2 INPUT OFFSET CURRENT (nA) INPUT OFFSET VOLTAGE (mV) 4 +125C 1 -55C 0 -1 +25C +125C -2 Input Bias Current 10 3 -3 -4 -5 -6 VS = 15V 10 VS = 15V 2 -55C 10 +25C +125C 1 10 10 3 2 -55C 10 +125C -7 +25C 0.1 -8 10A 100A .1A 1A 1000A 1 1000A 5 +125C 10 3 +25C -55C 10 PEAK OUTPUT VOLTAGE AND COMMON-MODE RANGE (V) VS = 15V 4 VOUT 3 VCMR 0 RLOAD = -1 TA = 25C -2 VCMR -4 -5 -6 100A 1000A (+)VIN = (-)VIN = VOUT = 36V VS = 15V -3 10A Leakage Current 10 5 2 1 .1A 1A AMPLIFIER BIAS CURRENT (IABC) Peak Output Voltage and Common-Mode Range Peak Output Current 10 2 100A AMPLIFIER BIAS CURRENT (I ABC) AMPLIFIER BIAS CURRENT (I ABC) 10 4 10A LEAKAGE CURRENT (pA) .1A 1A PEAK OUTPUT CURRENT ( A) Input Bias Current 10 4 INPUT BIAS CURRENT (nA) Input Offset Voltage 5 10 4 10 3 0V 10 2 VOUT -7 .1A 1A 10A 100A .1A 1A AMPLIFIER BIAS CURRENT (IABC) Input Leakage TRANSCONDUCTANCE (gM) -- ( ohm) INPUT LEAKAGE CURRENT (pA) +125C 10 3 10 2 +25C 10 August 31, 1994 100A 1000A 7 Transconductance 10 5 gM 10 4 mq m M VS = 15V +125C -55C +25C .1A 1A 10A 100A 1000A AMPLIFIER BIAS CURRENT (I ABC) 96 Input Resistance PINS 2, 15 OPEN 10 10 2 0C 25C 50C 75C100C125C AMBIENT TEMPERATURE (TA) 10 2 PINS 2, 15 OPEN 10 3 10 1 1 2 3 4 5 6 INPUT DIFFERENTIAL VOLTAGE 10A AMPLIFIER BIAS CURRENT (I ABC) 10 4 0 10 -50C -25C -8 1000A INPUT RESISTANCE (MEG ) 1 1 1 .1 .01 .1A 1A 10A 100A 1000A AMPLIFIER BIAS CURRENT (I ABC) Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Amplifier Bias Voltage vs Amplifier Bias Current 7 2000 100 VS = 15V 1800 TA = +25C RL = 10k OUTPUT DISTORTION (%) 6 -55C 1600 1400 CAPACITANCE (pF) AMPLIFIER BIAS VOLTAGE (mV) Distortion vs Differential Input Voltage Input and Output Capacitance +25C 1200 1000 +125C 800 600 5 CIN 4 COUT 3 2 IABC = 1mA 10 1 0.1 400 1 200 0 .1A 1A 10A 100A 1000A 0 0.01 .1A 1A 10A 100A 1000A AMPLIFIER BIAS CURRENT (I ABC) AMPLIFIER BIAS CURRENT (I ABC) Voltage vs Amplifier Bias Current 0 Noise vs Frequency 600 VS = 15V OUTPUT NOISE CURRENT (pA/Hz) OUTPUT VOLTAGE RELATIVE TO 1 VOLT RMS (dB) 20 RL = 10k VIN = 80mVP-P -20 VIN = 40mVP-P -40 -60 OUTPUT NOISE 20kHz BW -80 -100 .1A 1A 10A 100A 500 400 300 200 100 0 10 1000A IABC AMPLIFIER BIAS CURRENT (A) August 31, 1994 1 10 100 1000 DIFFERENTIAL INPUT VOLTAGE (mVP-P) 97 IABC = 1mA IABC = 100A 100 1k 10k FREQUENCY (Hz) 100k Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A TYPICAL PERFORMANCE CHARACTERISTICS (Continued) +36V 4, 13 A +15V 4V - 11 4, 13 A 5, 12 2, 15 - 5, 12 2, 15 NE5517 NE5517 8, 9 1, 15 3, 14 1, 10 3, 14 6 + 11 7, 10 6 + -15V Leakage Current Test Circuit Differential Input Current Test Circuit V+ V 50k V- Buffer VBE Test Circuit APPLICATIONS +15V INPUT 0.01F 3, 14 10k 62k - 390pF 51 11 1, 16 2, 15 7, 10 NE5517 1.3k 5, 12 4, 13 8, 9 OUTPUT 6 0.01F + 5k -15V 10k -15V 0.001F Unity Gain Follower Where VIN is the difference of the two input voltages The circuit schematic diagram of one-half of the NE5517, a dual KT 26mV at room temperature (300k). operational transconductance amplifier with linearizing diodes and Transistors Q1, Q2 and diode D1 form a current mirror which focuses impedance buffers, is shown in Figure 1. the sum of current I4 and I5 to be equal to amplifier bias current IB: CIRCUIT DESCRIPTION 1. Transconductance Amplifier I4 + I5 = IB The transistor pair, Q4 and Q5, forms a transconductance stage. The ratio of their collector currents (I4 and I5, respectively) is defined by the differential input voltage, VIN, which is shown in equation 1. I5 KT V IN q In I4 August 31, 1994 (2) If VIN is small, the ratio of I5 and I4 will approach unity and the Taylor series of In function can be approximated as I5 KT KT I 5 I 4 q In I 4 q I4 (1) 98 (3) Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier and I4 I5 IB The only limitation is that the signal current should not exceed ID. KT I 5 KT I 5 * I 4 2KT I 5 * I 4 + V(4) IN q In I 4 [ q 1 2I + q IB B q IB I 5 * I 4 + V IN 2KT 3. Impedance Buffer The upper limit of transconductance is defined by the maximum value of IB (2mA). The lowest value of IB for which the amplifier will function therefore determines the overall dynamic range. At low values of IB, a buffer with very low input bias current is desired. A Darlington amplifier with constant-current source (Q14, Q15, Q16, D7, D8, and R1) suits the need. The remaining transistors (Q6 to Q11) and diodes (D4 to D6) form three current mirrors that produce an output current equal to I5 minus I4. Thus: V IN I B q 2KT NE5517/5517A APPLICATIONS Voltage-Controlled Amplifier (5) + IO I B q In Figure 3, the voltage divider R2, R3 divides the input-voltage into small values (mV range) so the amplifier operates in a linear manner. The term 2KT is then the transconductance It is: of the amplifier and is proportional to IB. I OUT + * V IN @ 2. Linearizing Diodes For VIN greater than a few millivolts, equation 3 becomes invalid and the transconductance increases non-linearly. Figure 2 shows how the internal diodes can linearize the transfer function of the operational amplifier. Assume D2 and D3 are biased with current sources and the input signal current is IS. Since R3 R2 ) R3 @ gM; V OUT + I OUT @ R L; A+ V OUT V IN + R3 R2 ) R3 @ gM @ R L I4 + I5 = IB and I5 - I4 = I0, that is: (3) gM = 19.2 IABC I4 = (IB - I0), I5 = (IB + I0) (gM in mhos for IABC in mA) Since gM is directly proportional to IABC, the amplification is controlled by the voltage VC in a simple way. For the diodes and the input transistors that have identical geometries and are subject to similar voltages and temperatures, the following equation is true: ID ) IS 1 2(I B ) I O) (6) T 2 KT In + q In q ID 1 2(I B * I O) * IS 2 ID 2 IB for |I S| t IO + IS 2 ID When VC is taken relative to -VCC the following formula is valid: I ABC + (V C * 1.2V) R1 The 1.2V is the voltage across two base-emitter baths in the current mirrors. This circuit is the base for many applications of the NE5517. V+ 11 D6 D4 Q14 Q6 Q10 Q12 Q13 7,10 8,9 Q7 Q11 2,15 VOUTPUT D3 D2 Q4 -INPUT 4,13 Q5 5,12 +INPUT 3,14 Q15 1,16 AMP BIAS INPUT Q16 Q3 Q2 D7 Q9 R1 Q1 D8 Q8 D1 D5 V- 6 August 31, 1994 Figure 1. Circuit Diagram of NE5517 99 Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier where gM is approximately 19.21 MHOs at room temperature. Figure 7 shows a Voltage Controlled Resistor using linearizing diodes. This improves the noise performance of the resistor. +VS ID I ID 2 * I ID S 2 I0 + 2 I ) I S I Voltage-Controlled Filters B Figure 8 shows a Voltage Controlled Low-Pass Filter. The circuit is a unity gain buffer until XC/gM is equal to R/RA. Then, the frequency response rolls off at a 6dB per octave with the -3dB point being defined by the given equations. Operating in the same manner, a Voltage Controlled High-Pass Filter is shown in Figure 9. Higher order filters can be made using additional amplifiers as shown in Figures 10 and 11. D I0 + I5 * I4 S I5 I4 D3 D2 1/2ID Q4 IS I5 Voltage-Controlled Oscillators IS Figure 12 shows a voltage-controlled triangle-square wave generator. With the indicated values a range from 2Hz to 200kHz is possible by varying IABC from 1mA to 10A. 1/2ID IB The output amplitude is determined by IOUT x ROUT. -VS Figure 2. Linearizing Diode Please notice the differential input voltage is not allowed to be above 5V. Stereo Amplifier With Gain Control With a slight modification of this circuit you can get the sawtooth pulse generator, as shown in Figure 13. Figure 4 shows a stereo amplifier with variable gain via a control input. Excellent tracking of typical 0.3dB is easy to achieve. With the potentiometer, RP, the offset can be adjusted. For AC-coupled amplifiers, the potentiometer may be replaced with two 510 resistors. APPLICATION HINTS To hold the transconductance gM within the linear range, IABC should be chosen not greater than 1mA. The current mirror ratio should be as accurate as possible over the entire current range. A current mirror with only two transistors is not recommended. A suitable current mirror can be built with a PNP transistor array which causes excellent matching and thermal coupling among the transistors. The output current range of the DAC normally reaches from 0 to -2mA. In this application, however, the current range is set through RREF (10k) to 0 to -1mA. Modulators Because the transconductance of an OTA (Operational Transconductance Amplifier) is directly proportional to IABC, the amplification of a signal can be controlled easily. The output current is the product from transconductancexinput voltage. The circuit is effective up to approximately 200kHz. Modulation of 99% is easy to achieve. Voltage-Controlled Resistor (VCR) Because an OTA is capable of producing an output current proportional to the input voltage, a voltage variable resistor can be made. Figure 6 shows how this is done. A voltage presented at the RX terminals forces a voltage at the input. This voltage is multiplied by gM and thereby forces a current through the RX terminals: RX = R ) gM ) NE5517/5517A I DACMAX + 2 @ V REF 5V +2@ + 1mA 10k R REF RA RA INT +VCC VC +VCC R1 R4 = R2/ /R3 3 + IABC 1 11 5 7 NE5517 R2 VIN - 4 6 8 IOUT VOUT RL RS R3 INT -VCC TYPICAL VALUES: R1 = 47k R2 = 10k R3 = 200 R4 = 200 RL = 100k RS = 47k Figure 3. August 31, 1994 100 Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A +VCC 10k 3 VIN1 RIN + 11 INT +VCC 15k NE5517/A RP +VCC 1k RD IABC - 8 1 4 30k VC VOUT1 RL 10k 5.1k RC 10k VIN2 14 RIN 15k RP +VCC 1k 16 + -VCC IABC 15 +VCC 10 NE5517/A 12 RD 6 - 9 13 VOUT2 RL 10k RS -VCC INT Figure 4. Gain-Controlled Stereo Amplifier RC 30k VIN2 SIGNAL 1 IABC +VCC 11 ID 3 15k 2 5 NE5517/A 1k VOS INT +VCC + 7 - VIN1 CARRIER 8 4 RL 10k 10k VOUT RS 6 -VCC -VCC INT Figure 5. Amplitude Modulator R 30k +VCC 3 + VC INT +VCC 11 IO 2 NE5517/A 5 7 C - 4 200 200 VOUT 8 -VCC RX R 100k 10k -VCC INT Figure 6. VCR August 31, 1994 101 X + R ) RA gM @ RA Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier +VCC 30k 1 VC +VCC ID 3 VOS NE5517/5517A RP INT +VCC 11 2 NE5517/A 1k 5 7 C 6 4 8 RX -VCC R 100k 10k -VCC INT Figure 7. VCR with Linearizing Diodes 1 +VCC 100k VIN 3 30k VC IABC INT +VCC 11 + 2 NE5517/A 5 - 6 200 8 VOUT 200 RA 7 C 150pF 4 R 100k -VCC 10k -VCC INT NOTE: f O g(R RA gM RA) 2C Figure 8. Voltage-Controlled Low-Pass Filter 1 +VCC +VCC 100k VOS NULL 3 + 30k VC IABC INT +VCC 11 2 NE5517/A 5 -VCC - 6 4 1k RA 1k 7 C 8 0.005F VOUT R 100k -VCC 10k -VCC INT NOTE: f O g(R RA gM RA) 2C Figure 9. Voltage-Controlled High-Pass Filter August 31, 1994 102 Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier NE5517/5517A 15k VC +VCC +VCC NE5517/A NE5517/A 100k C - 200 R 100k -VCC RA 2C - 100pF 200 INT +VCC + + VIN 200pF VOUT RA 100k RA 10k 10k 200 200 -VCC INT -VCC NOTE: f O (R R A gM R A) 2 C Figure 10. Butterworth Filter - 2nd Order 1 15k 16 VC +VCC +VCC 10k 3 14 + 11 5 2 7 12 NE5517/A - INT +VCC + 6 - 800pF 10 NE5517/A 15 20k LOW PASS VOUT 800pF 13 9 1k -VCC 1k 5.1k 20k 20k 5.1k -VCC -VCC INT BANDPASS OUT Figure 11. State Variable Filter 30k +VCC VC +VCC 4 - INT +VCC 13 11 1 5 7 12 + 6 -VCC 10 NE5517/A NE5517/A 3 INT +VCC 47k - C 0.1F + 8 16 14 20k VOUT2 9 10k -VCC VOUT1 -VCC INT GAIN CONTROL Figure 12. Triangle-Square Wave Generator (VCO) August 31, 1994 103 Philips Semiconductors Linear Products Product specification Dual operational transconductance amplifier IC NE5517/5517A IB 470k 1 +VCC VC +VCC 4 + 3 R1 30k 6 -VCC +VCC 30k 11 - 7 12 10 NE5517/A NE5517/A - INT 47k 13 5 2 16 INT +VCC C 0.1F + 8 14 R2 20k 30k -VCC -VCC VOUT1 NOTE: (V V PK + * 0.8) R 1 I 2V PK x C 2V PKxC C C T + T + f I t H L OSC 2V xC C R1 ) R2 IB I PK C VOUT2 INT t I B Figure 13. Sawtooth Pulse VCO August 31, 1994 104