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S E M I C O N D U C T O R

ICL7611, ICL7612
ICL76XX Series Low Power CMOS Operational Amplifiers
Description
12

March 1993

Features
· Wide Operating Voltage Range . . . . . . . . . . . .±1V to ±8V · High Input Impedance . . . . . . . . . . . . . . . . . . . . . .10

· Programmable Power Consumption . . . .Low as 20µW · Input Current Lower Than BIFIETs. . . . . . . . . . 1pA Typ · Output Voltage Swing . . . . . . . . . . . . . . . . . . . V+ and V· Input Common Mode Voltage Range Greater Than Supply Rails (ICL7612)

The ICL761X/762X/764X series is a family of monolithic CMOS operational amplifiers. These devices provide the designer with high performance operation at low supply voltages and selectable quiescent currents, and are an ideal design tool when ultra low input current and low power dissipation are desired. The basic amplifier will operate at supply voltages ranging from ±1V to ±8V, and may be operated from a single Lithium cell. A unique quiescent current programming pin allows setting of standby current to 1mA, 100µA, or 10µA, with no external components. This results in power consumption as low as 20µW. The output swing ranges to within a few millivolts of the supply voltages. Of particular significance is the extremely low (1pA) input current, input noise current of 0.01pA/Hz, and 1012 input impedance. These features optimize performance in very high source impedance applications. The inputs are internally protected. Outputs are fully protected against short circuits to ground or to either supply. AC performance is excellent, with a slew rate of 1.6V/µs, and unity gain bandwidth of 1MHz at IQ = 1mA. Because of the low power dissipation, junction temperature rise and drift are quite low. Applications utilizing these features may include stable instruments, extended life designs, or high density packages.

Applications
· Portable Instruments · Telephone Headsets · Hearing Aid/Microphone Amplifiers · Meter Amplifiers · Medical Instruments · High Impedance Buffers

Pinouts (See Ordering Information on Next Page)
ICL7611, ICL7612 (PDIP, SOIC) TOP VIEW ICL7611, ICL7612 (METAL CAN) TOP VIEW
IQ SET 8 BAL -IN +IN V1 2 3 4 + 8 7 6 5 IQ SET V+ OUT BAL -IN 2 BAL 1 + 3 4 V5 7 V+

6

OUT

+IN

BAL

CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper I.C. Handling Procedures. Copyright

© Harris Corporation 1993

File Number

2919.1

2-670

ICL7611, ICL7612 Ordering Information
PART NUMBER ICL7611ACPA ICL7611BCPA ICL7611DCPA ICL7611ACTV ICL7611BCTV ICL7611DCTV ICL7611AMTV ICL7611BMTV ICL7611DMTV ICL7611DCBA ICL7611DCBA-T ICL7612ACPA ICL7612BCPA ICL7612DCPA ICL7612ACTV ICL7612BCTV ICL7612DCTV ICL7612AMTV ICL7612BMTV ICL7612DMTV ICL7612DCBA ICL7612DCBA-T TEMPERATURE RANGE 0oC to +70oC 0 C to +70 C 0oC to +70oC 0 C to +70 C 0oC to +70oC 0 C to +70 C -55oC to +125oC -55 C to +125 C -55oC to +125oC 0 C to +70 C 0oC to +70oC 0 C to +70 C 0oC to +70oC 0 C to +70 C 0oC to +70oC 0 C to +70 C 0oC to +70oC -55 C to +125 C -55oC to +125oC -55 C to +125 C 0oC to +70oC 0 C to +70 C
o o o o o o o o o o o o o o o o o o o o o o

PACKAGE 8 Lead Plastic DIP - A Grade 8 Lead Plastic DIP - B Grade 8 Lead Plastic DIP - D Grade 8 Pin TO-99 Metal Can - A Grade 8 Pin TO-99 Metal Can - B Grade 8 Pin TO-99 Metal Can - D Grade 8 Pin TO-99 Metal Can - A Grade 8 Pin TO-99 Metal Can - B Grade 8 Pin TO-99 Metal Can - D Grade 8 Lead SOIC - D Grade 8 Lead SOIC - D Grade - Tape and Reel 8 Lead Plastic DIP - A Grade 8 Lead Plastic DIP - B Grade 8 Lead Plastic DIP - D Grade 8 Lead TO-99 Metal Can - A Grade 8 Lead TO-99 Metal Can - B Grade 8 Lead TO-99 Metal Can - D Grade 8 Lead TO-99 Metal Can - A Grade 8 Lead TO-99 Metal Can - B Grade 8 Lead TO-99 Metal Can - D Grade 8 Lead SOIC - D Grade 8 Lead SOIC - D Grade - Tape and Reel

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Specifications ICL7611, ICL7612
Absolute Maximum Ratings
Supply Voltage V+ to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18V Input Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . V- -0.3 to V+ +0.3V Differential Input Voltage (Note 1) . . . . . . . . .[(V+ +0.3) - (V- -0.3)]V Duration of Output Short Circuit (Note 2) . . . . . . . . . . . . . . Unlimited Power Dissipation At TA = +25oC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250mW Above TA = +25oC. . . . . . . . . . . . . . . . . . Derate Linearly 2mW/oC Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +175oC Junction Temperature (Plastic Package) . . . . . . . . . . . . . . . +150oC Lead Temperature (Soldering 10 Sec.). . . . . . . . . . . . . . . . . +300oC

Operating Conditions
Operating Temperature Range ICL76XXM . . . . . . . . . . . . . . . . . . . . . . . . . . -55oC TA +125oC ICL76XXC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0oC TA +70oC Storage Temperature Range. . . . . . . . . . . . . . -65oC TA +150oC

CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

Electrical Specifications

VSUPPLY = ±5.0V, TA= +25oC, Unless Otherwise Specified ICL7611A, ICL7612A MIN o

PARAMETERS Input Offset Voltage

SYMBOL VOS VOS/T IOS

TEST CONDITIONS RS 100k, TA = +25 C
o

ICL7611B, ICL7612B

ICL7611D, ICL7612D TYP MAX UNITS 25 0.5 15 20 30 300 800 1.0 50 400 4000 mV mV µV/oC pA pA pA pA pA pA V V V V V V V V V V V V V V V

TYP MAX MIN 10 0.5 1.0 2 3 30 300 800 50 400 4000 ±4.4 ±4.2 ±3.7 ±5.3 +5.3, -5.1 +5.3, -4.5 ±4.9 ±4.8 ±4.7 ±4.9 ±4.8 ±4.5 ±4.5 ±4.3 ±4.0

TYP MAX MIN 15 0.5 5 7 30 300 800 1.0 50 400 4000 ±4.4 ±4.2 ±3.7 ±5.3 +5.3, -5.1 +5.3, -4.5 ±4.9 ±4.8 ±4.7 ±4.9 ±4.8 ±4.5 ±4.5 ±4.3 ±4.0

TMIN TA TMAX Temperature Coefficient of VOS Input Offset Current RS 100k TA = +25oC 0 C to +70 C -55 C to +125 C Input Bias Current IBIAS TA = +25 C 0 C to +70 C -55 C to +125 C Common Mode Voltage Range (Except ICL7612) Extended Common Mode Voltage Range (ICL7612 Only) VCMR IQ = 10µA IQ = 100µA IQ = 1mA VCMR IQ = 10µA IQ = 100µA IQ = 1mA Output Voltage Swing VOUT IQ = 10µA, RL = 1M TA = +25oC 0 C to 70 C -55oC to +125oC IQ = 100µA, RL = 100k TA = +25oC 0 C to 70 C -55 C to +125 C IQ = 1mA, RL = 10k TA = +25 C 0 C to 70 C -55 C to +125 C
o o o o o o o o o o o o o o o o o o o

±4.4 ±4.2 ±3.7 ±5.3 +5.3, -5.1 +5.3, -4.5 ±4.9 ±4.8 ±4.7 ±4.9 ±4.8 ±4.5 ±4.5 ±4.3 ±4.0

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Specifications ICL7611, ICL7612
Electrical Specifications
VSUPPLY = ±5.0V, TA= +25oC, Unless Otherwise Specified (Continued) ICL7611A, ICL7612A MIN 86 80 74 86 80 74 80 76 72 RS 100k, IQ = 10µA RS 100k, IQ = 100µA RS 100k, IQ = 1mA Power Supply Rejection Ratio VSUPPLY = ±8V to ±2V Input Referred Noise Voltage Input Referred Noise Current Supply Current PSRR RS 100k, IQ = 10µA RS 100k, IQ = 100µA RS 100k, IQ = 1mA eN iN ISUPPLY RS = 100, f = 1kHz RS = 100, f = 1kHz No Signal, No Load IQ SET = +5V, Low Bias IQ SET = 0V, Medium Bias IQ SET = -5V , High Bias Channel Separation Slew Rate VO1/VO2 SR AV = 100 IQ = 10µA, AV = 1, CL = 100pF RL = 1M VIN = 8VP-P IQ = 100µA, RL = 100k IQ = 1mA, RL = 10k Rise Time tR VIN = 50mV, IQ = 10µA, CL = 100pF RL = 1M IQ = 100µA, RL = 100k IQ = 1mA, RL = 10k 76 76 66 80 80 70 ICL7611B, ICL7612B ICL7611D, ICL7612D TYP MAX UNITS 104 102 83 0.044 0.48 1.4 10
12

PARAMETERS Large Signal Voltage Gain

SYMBOL AVOL

TEST CONDITIONS VO = ±4.0V, TA = +25 C RL = 1M, 0oC to 70oC IQ = 10µA -55oC to +125oC
o

TYP MAX MIN 104 102 83 0.044 0.48 1.4 10
12

TYP MAX MIN 104 102 83 0.044 0.48 1.4 10
12

0.02 0.25 2.5 -

80 75 68 80 75 68 76 72 68 70 70 60 80 80 70 -

0.02 0.25 2.5 -

80 75 68 80 75 68 76 72 68 70 70 60 80 80 70 -

0.02 0.25 2.5 -

dB dB dB dB dB dB dB dB dB MHz MHz MHz dB dB dB dB dB dB nV/Hz pA/Hz mA mA mA dB V/µs V/µs V/µs µs µs µs

VO = ±4.0V, TA = +25 C RL = 100k, o 0 C to 70oC IQ = 100µA -55oC to +125oC
o

VO = ±4.0V, TA = +25oC RL = 10k, 0oC to 70oC IQ = 1mA -55oC to +125oC Unity Gain Bandwidth GBW IQ = 10µA IQ = 100µA IQ = 1mA Input Resistance Common Mode Rejection Ratio RIN CMRR

96 91 87 94 86 77 100 0.01 0.01 0.1 1.0 120 0.016 0.16 1.6 20 2 0.9

96 91 87 94 86 77 100 0.01 0.01 0.1 1.0 120 0.016 0.16 1.6 20 2 0.9

96 91 87 94 86 77 100 0.01 0.01 0.1 1.0 120 0.016 0.16 1.6 20 2 0.9

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Specifications ICL7611, ICL7612
Electrical Specifications
VSUPPLY = ±5.0V, TA= +25oC, Unless Otherwise Specified (Continued) ICL7611A, ICL7612A MIN ICL7611B, ICL7612B ICL7611D, ICL7612D TYP MAX UNITS 5 10 40 % % %

PARAMETERS Overshoot Factor

SYMBOL OS

TEST CONDITIONS VIN = 50mV, IQ = 10µA, CL = 100pF RL = 1M IQ = 100µA, RL = 100k IQ = 1mA, RL = 10k

TYP MAX MIN 5 10 40 -

TYP MAX MIN 5 10 40 -

NOTES: 1. Long term offset voltage stability will be degraded if large input differential voltages are applied for long periods of time. 2. The outputs may be shorted to ground or to either supply, for VSUPP 10V. Care must be taken to insure that the dissipation rating is not exceeded.

Electrical Specifications

VSUPPLY = ±1.0V, IQ = 10µA, TA= +25oC, Unless Otherwise Specified TEST CONDITIONS RS 100k TA = +25 C
o

ICL7611A, ICL7612A MIN ±0.6 +0.6 to -1.1 TYP 10 0.5 1.0 90 80 0.044 10
12

ICL7611B, ICL7612B MIN ±0.6 +0.6 to -1.1 ±0.98 ±0.96 TYP 15 0.5 1.0 90 80 0.044 10
12

PARAMETERS Input Offset Voltage

SYMBOL VOS VOS/T IOS

MAX 2 3 30 300 50 500 15 -

MAX 5 7 30 300 50 500 15 -

UNITS mV mV µV/oC pA pA pA pA V V V V dB dB MHz dB dB nV/Hz pA/Hz µA V/µs µs %

TMIN TA TMAX Temperature Coefficient of VOS Input Offset Current RS 100k TA = +25oC 0oC to +70oC Input Bias Current IBIAS TA = +25oC 0 C to +70 C Common Mode Voltage Range (Except ICL7612) Extended Common Mode Voltage Range (ICL7612 Only) Output Voltage Swing VCMR VCMR VOUT RL = 1M TA = +25oC 0 C to +70 C Large Signal Voltage Gain AVOL VO = ±0.1V, TA = +25 C RL = 1M 0oC to +70oC
o o o o o

±0.98 ±0.96 -

Unity Gain Bandwidth Input Resistance Common Mode Rejection Ratio Power Supply Rejection Ratio Input Referred Noise Voltage Input Referred Noise Current Supply Current Slew Rate Rise Time Overshoot Factor

GBW RIN CMRR PSRR eN iN ISUPPLY SR tR OS RS 100k RS 100k RS = 100, f = 1kHz RS = 100, f = 1kHz No Signal, No Load AV = 1, CL = 100pF, VIN = 0.2VP-P, RL = 1M VIN = 50mV, CL = 100pF RL = 1M VIN = 50mV, CL = 100pF, RL = 1M

-

80 80 100 0.01 6 0.016 20 5

80 80 100 0.01 6 0.016 20 5

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Specifications ICL7611, ICL7612 Functional Diagram
IQ INPUT STAGE SETTING STAGE OUTPUT STAGE V+ 3K BAL P1 V+ +INPUT n1 n2 P1 3K 900K BAL P3 P5 P6 100K P4 P9 CFF = 9pF OUTPUT VV+ CC = 33pF P7 P8 6.3V

-INPUT n4 n5 n6 n7 n9 n10 6.3V n3 n8 Vn11

V-

V+

IQ SET

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ICL7611, ICL7612 Typical Performance Curves
10K TA = +25oC NO LOAD NO SIGNAL SUPPLY CURRENT (µA) 1K IQ = 1mA SUPPLY CURRENT (µA) 103 104 V+ - V- = 10V NO LOAD NO SIGNAL IQ = 1mA

IQ = 100µA 100

102

IQ = 100µA

IIQ = 10µA Q = 1mA 10

10

IQ = 10µA

1 0 2 4 6 8 10 12 SUPPLY VOLTAGE (V) 14 16

1 -50

-25

0

+25

+50

+75

+100

+125

FREE-AIR TEMPERATURE (oC)

FIGURE 1. SUPPLY CURRENT PER AMPLIFIER vs SUPPLY VOLTAGE

FIGURE 2.

SUPPLY CURRENT PER AMPLIFIER vs FREE-AIR TEMPERATURE

1000 DIFFERENTIAL VOLTAGE GAIN (kV/V) V+ = +5V V- = -5V INPUT BIAS CURRENT (pA) 100

1000 VSUPP = 10V VOUT = 8V RL = 1M IQ = 10µA 100 RL = 100k IQ = 100µA RL = 10k IQ = 1mA 10

10

1.0

0.1 -50

-25

0

+25

+50

+75

+100

+125

1 -75

-50

-25

0

+25

+50

+75

+100 +125

FREE-AIR TEMPERATURE (oC)

FREE-AIR TEMPERATURE (oC)

FIGURE 3. INPUT BIAS CURRENT vs TEMPERATURE

FIGURE 4. LARGE SIGNAL DIFFERENTIAL VOLTAGE GAIN vs FREE-AIR TEMPERATURE

107 COMMON MODE REJECTION RATIO (dB) DIFFERENTIAL VOLTAGE GAIN (V/V) 106 105 IQ = 100µA PHASE SHIFT (DEGREES) 104 103 102 10 1 0.1 IQ = 1mA 0 45 PHASE SHIFT (IQ = 1mA) 90 135 IQ = 10µA 1.0 10 100 1k 10k FREQUENCY (Hz) 100k 180 1M TA = +25oC VSUPP = 15V

105 VSUPP = 10V 100 IQ = 10µA 95 IQ = 100µA 90 85 80 75 70 -75 IQ = 1mA

-50

-25

0

+25

+50

+75

+100 +125

FREE-AIR TEMPERATURE (oC)

FIGURE 5. LARGE SIGNAL FREQUENCY RESPONSE

FIGURE 6. COMMON MODE REJECTION RATIO vs FREE-AIR TEMPERATURE

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ICL7611, ICL7612 Typical Performance Curves
100 SUPPLY VOLTAGE REJECTION RATIO (dB) IQ = 1mA 95 90 85 IQ = 10µA 80 75 70 65 -75 VSUPP = 10V

(Continued)
EQUIVALENT INPUT NOISE VOLTAGE (nV/Hz) 600 TA = +25oC 3V VSUPP 16V

500

IQ = 100µA

400

300

200

100

-50

-25

0

+25

+50

+75

+100

+125

0 10 100 1k FREQUENCY (Hz) 10k 100k

FREE-AIR TEMPERATURE (oC)

FIGURE 7. POWER SUPPLY REJECTION RATIO vs FREE-AIR TEMPERATURE

FIGURE 8. EQUIVALENT INPUT NOISE VOLTAGE vs FREQUENCY

16 MAXIMUM OUTPUT VOLTAGE (VP-P) MAXIMUM OUTPUT VOLTAGE (VP-P) 14 12 10 8 6 4 2 0 100 VSUPP = ±2V 1k 10k 100k FREQUENCY (Hz) 1M 10M VSUPP = ±5V VSUPP = ±8V TA = +25oC IQ = 1mA IQ = 10µA IQ = 100µA

16 14 12 10 8 6 4 2 0 10k TA = -55oC TA = +25oC TA = +125oC VSUPP = 10V IQ = 1mA

100k

1M

10M

FREQUENCY (Hz)

FIGURE 9. OUTPUT VOLTAGE vs FREQUENCY

FIGURE 10. OUTPUT VOLTAGE vs FREQUENCY

16 TA = +25oC MAXIMUM OUTPUT VOLTAGE (VP-P) 14 12 10 8 6 4 RL = 100k - 1M MAXIMUM OUTPUT VOLTAGE (VP-P)

12 RL = 100k 10

8

RL = 10k

6 RL = 2k 4 VSUPP = 10V IQ = 1mA

RL = 10k

2

2

4

6

8 10 12 SUPPLY VOLTAGE (V)

14

16

0 -75

-50

-25 0 +25 +50 +75 FREE-AIR TEMPERATURE (oC)

+100 +125

FIGURE 11. OUTPUT VOLTAGE vs SUPPLY VOLTAGE

FIGURE 12. OUTPUT VOLTAGE vs FREE-AIR TEMPERATURE

2-677

ICL7611, ICL7612 Typical Performance Curves
MAXIMUM OUTPUT SOURCE CURRENT (mA) 40 MAXIMUM OUTPUT SINK CURRENT (mA)

(Continued)
0.01

30

IQ = 10µA 0.1

20

IQ = 100µA 1.0

10

IQ = 1mA 10 0 2 4 6 8 10 12 SUPPLY VOLTAGE (V) 14 16

0 0 2 4 6 8 10 12 SUPPLY VOLTAGE (V) 14 16

FIGURE 13. OUTPUT SOURCE CURRENT vs SUPPLY VOLTAGE

FIGURE 14. OUTPUT SINK CURRENT vs SUPPLY VOLTAGE

16 MAXIMUM OUTPUT VOLTAGE (VP-P) 14 12 10 8 6 4 2 0 0.1 TA = +25oC V+ - V- = 10V IQ = 1mA

8 INPUT AND OUTPUT VOLTAGE (V) 6 4 2 0 -2 INPUT -4 -6 1.0 10 LOAD RESISTANCE (k) 100 0 2 4 6 TIME (µs) 8 10 12 OUTPUT TA = +25oC, VSUPP = 10V RL = 10k, CL = 100pF

FIGURE 15. OUTPUT VOLTAGE vs LOAD RESISTANCE

FIGURE 16. VOLTAGE FOLLOWER LARGE SIGNAL PULSE RESPONSE (IQ = 1mA)

8 INPUT AND OUTPUT VOLTAGE (V) INPUT AND OUTPUT VOLTAGE (V) 6 4 2 OUTPUT 0 -2 INPUT -4 -6 0 20 40 60 TIME (µs) 80 100 120 TA = +25oC, VSUPP = 10V RL = 100k, CL = 100pF

8 6 4 2 OUTPUT 0 INPUT -2 -4 -6 0 200 400 600 TIME (µs) 800 1000 1200 TA = +25oC, VSUPP = 10V RL = 1M, CL = 100pF

FIGURE 17. VOLTAGE FOLLOWER LARGE SIGNAL PULSE RESPONSE (IQ = 100µA)

FIGURE 18. VOLTAGE FOLLOWER LARGE SIGNAL PULSE RESPONSE (IQ = 10µA)

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ICL7611, ICL7612 Detailed Description
Static Protection All devices are static protected by the use of input diodes. However, strong static fields should be avoided, as it is possible for the strong fields to cause degraded diode junction characteristics, which may result in increased input leakage currents. Latchup Avoidance Junction-isolated CMOS circuits employ configurations which produce a parasitic 4-layer (p-n-p-n) structure. The 4layer structure has characteristics similar to an SCR, and under certain circumstances may be triggered into a low impedance state resulting in excessive supply current. To avoid this condition, no voltage greater than 0.3V beyond the supply rails may be applied to any pin. In general, the opamp supplies must be established simultaneously with, or before any input signals are applied. If this is not possible, the drive circuits must limit input current flow to 2mA to prevent latchup. Choosing the Proper IQ The ICL7611 and ICL7612 have a similar IQ set-up scheme, which allows the amplifier to be set to nominal quiescent currents of 10µA, 100µA or 1mA. These current settings change only very slightly over the entire supply voltage range. The ICL7611/12 have an external IQ control terminal, permitting user selection of quiescent current. To set the IQ connect the IQ terminal as follows: IQ = 10µA - IQ pin to V+ IQ = 100µA - IQ pin to ground. If this is not possible, any voltage from V+ - 0.8 to V- +0.8 can be used. IQ = 1mA - IQ pin to VNOTE: The output current available is a function of the quiescent current setting. For maximum p-p output voltage swings into low impedance loads, IQ of 1mA should be selected. Output Stage and Load Driving Considerations Each amplifiers' quiescent current flows primarily in the output stage. This is approximately 70% of the IQ settings. This allows output swings to almost the supply rails for output loads of 1M, 100k, and 10k, using the output stage in a highly linear class A mode. In this mode, crossover distortion is avoided and the voltage gain is maximized. However, the output stage can also be operated in Class AB for higher output currents. (See graphs under Typical Operating Characteristics). During the transition from Class A to Class B operation, the output transfer characteristic is non-linear and the voltage gain decreases. Input Offset Nulling Offset nulling may be achieved by connecting a 25K pot between the BAL terminals with the wiper connected to V+. At quiescent currents of 1mA the nulling range provided is adequate for all VOS selections; however with IQ = 10µA and 100µA, nulling may not be possible with higher values of VOS.
1M

Frequency Compensation The ICL7611 and ICL7612 are internally compensated, and are stable for closed loop gains as low as unity with capacitive loads up to 100pF. Extended Common Mode Input Range The ICL7612 incorporates additional processing which allows the input CMVR to exceed each power supply rail by 0.1V for applications where VSUPP ±1.5V. For those applications where VSUPP ±1.5V the input CMVR is limited in the positive direction, but may exceed the negative supply rail by 0.1V in the negative direction (e.g. for VSUPP = ±1.0V, the input CMVR would be +0.6V to -1.1V). Operation At VSUPP = ±1.0V Operation at VSUPP = ±1.0V is guaranteed at IQ = 10µA for A and B grades only. Output swings to within a few millivolts of the supply rails are achievable for RL 1M. Guaranteed input CMVR is ±0.6V minimum and typically +0.9V to -0.7V at VSUPP = ±1.0V. For applications where greater common mode range is desirable, refer to the description of ICL7612 above.

Applications
The user is cautioned that, due to extremely high input impedances, care must be exercised in layout, construction, board cleanliness, and supply filtering to avoid hum and noise pickup. Note that in no case is IQ shown. The value of IQ must be chosen by the designer with regard to frequency response and power dissipation.

VIN

+ ICL7612 RL 10k VOUT

FIGURE 19. SIMPLE FOLLOWER*

+5 VIN 100k -

+5

ICL7612 +

VOUT TO CMOS OR LPTTL LOGIC

FIGURE 20. LEVEL DETECTOR* * By using the ICL7612 in this application, the circuit will follow rail to rail inputs.

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ICL7611, ICL7612

ICL7611 + 1M

1M ICL7611 +

1µF + -



ICL7611 +

VOUT

1M VV+ DUTY CYCLE 680k WAVEFORM GENERATOR

* Low leakage currents allow integration times up to several hours.

Since the output range swings exactly from rail to rail, frequency and duty cycle are virtually independent of power supply variations. FIGURE 22. PRECISE TRIANGLE/SQUARE WAVE GENERATOR

FIGURE 21. PHOTOCURRENT INTEGRATOR

1M VOH 0.5µF 10k VIN 2.2M 20k TO SUCCEEDING INPUT STAGE VOL COMMON ICL7611 + -8V V+ TA = +125oC OUT IQ - V+8V

+ ICL7611 -

10µF 1.8k = 5% SCALE ADJUST

20k

+ V+

FIGURE 23. AVERAGING AC TO DC CONVERTER FOR A/D CONVERTERS SUCH AS ICL7106, ICL7107, ICL7109, ICL7116, ICL7117

FIGURE 24. BURN-IN AND LIFE TEST CIRCUIT

VIN + BAL 25k VOUT

BAL

V+

FIGURE 25. VOS NULL CIRCUIT

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ICL7611, ICL7612

0.2µF

0.2µF

0.2µF

30k

160k + ICL7611 360k 680k 100k 51k + ICL7611 -

INPUT

0.1µF

0.2µF

0.1µF

1M OUTPUT 1M

*
360k

*

The low bias currents permit high resistance and low capacitance values to be used to achieve low frequency cutoff. fC = 10Hz, AVCL = 4, Passband ripple = 0.1dB. *Note that small capacitors (25 - 50pF) may be needed for stability in some cases. FIGURE 26. FIFTH ORDER CHEBYSHEV MULTIPLE FEEDBACK LOW PASS FILTER

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