ICL7611DESA+

Overview

The ICL7611DESA+ is a single-channel, low-power monolithic CMOS operational amplifier manufactured by Analog Devices Inc./Maxim Integrated. It operates within a supply voltage range of ±1V to ±8V or 2V to 16V single supply. Key electrical parameters include a typical input bias current of 1pA (max 4nA at +125°C), an input offset voltage of 15mV, and a unity-gain bandwidth of 0.044MHz at the lowest quiescent current setting. The device features programmable quiescent currents of 10μA, 100μA, or 1000μA per amplifier, allowing optimization for power consumption versus speed.

Feature Summary

• Ultra-low input bias current of 1pA typical ensures minimal loading on high-impedance sources.
• Programmable quiescent current allows selection between 10μA, 100μA, and 1000μA to balance power and performance.
• CMOS output stage provides rail-to-rail swing capability, approaching supply voltages within millivolts.
• Monolithic design offers industry-standard pinouts for direct replacement in existing circuits.

Applications

• Long time constant integrators
• Picoammeters
• Low droop rate sample/hold amplifiers
• pH meters and photodiode amplifiers

Procurement Notes

Verify the specific suffix 'DESA+' against the manufacturer's official ordering information to confirm the package type, temperature range, and RoHS compliance status. Confirm availability through authorized distributors as production status may vary. Ensure the selected variant matches the required quiescent current configuration for the target application.

Selection Notes

Select this component when ultra-low input bias current and low power consumption are critical requirements. The programmable IQ feature allows designers to optimize the trade-off between bandwidth/slew rate and power dissipation. Verify that the 15mV maximum input offset voltage meets the precision requirements of the specific circuit application.

Part Context

This part belongs to the ICL761X–ICL764X family of single/dual/triple/quad operational amplifiers. The family is characterized by its monolithic CMOS construction, which enables the combination of extremely low input currents with wide supply voltage operation. The ICL7611 specifically denotes the single-channel version of this architecture.

Replacement Considerations

The datasheet identifies the device as having an industry-standard pinout and being a second source for similar architectures. Cross-reference with other manufacturers offering pin-compatible CMOS op-amps with comparable bias current specifications if sourcing is restricted.

FAQ

How is the quiescent current configured?

For the ICL7611, the quiescent current is programmable via the IQ pin. Connecting the IQ pin to V+ selects 10μA, connecting it between V- + 0.8V and V+ - 0.8V selects 100μA, and connecting it to V- selects 1000μA.

Does the ICL7611 support input offset nulling?

Yes, the input offset can be nulled by connecting a 25kΩ potentiometer between the OFFSET terminals with the wiper connected to V+. This method is effective at quiescent currents of 100μA and 1mA.