Analog Devices Inc./Maxim Integrated ICL7642ECPD+

Overview

ICL7642ECPD+ from Maxim Integrated is a quad CMOS operational amplifier optimized for ultra-low input bias current (1 pA typical), programmable quiescent current (10 μA / 100 μA / 1 mA per amplifier), and rail-to-rail output swing - operating from ±1V to ±8V or 2V–16V single supply. It delivers 0.044 MHz unity-gain bandwidth at 10 μA IQ and supports precision pH meter front-ends, picoammeter circuits, and low-droop sample/hold amplifiers.

For engineers reviewing the ICL7642ECPD+ datasheet, ICL7642ECPD+ pinout, ICL7642ECPD+ application, or ICL7642ECPD+ equivalent, key selection criteria include confirmed 1 pA input bias current, 14-pin plastic DIP package with industry-standard pinout, temperature range of –40°C to +85°C, and verified compatibility with high-impedance sensor interfaces requiring sub-picoampere leakage control.

Technical Context

The ICL7642ECPD+ belongs to the ICL761X–ICL764X family of monolithic CMOS op amps, featuring pin-selectable quiescent current via external voltage on dedicated IQ pins (for singles/triples) - though the ICL7642 quad variant uses fixed IQ settings per channel. Its architecture enables stable unity-gain operation without external compensation.

It achieves ultra-low input bias current through CMOS input stages and offers 10¹² Ω input impedance, 0.01 pA/√Hz input noise current, and common-mode rejection ratio up to 96 dB - all critical for photodiode amplification and long-time-constant integrators where input leakage dominates error budgets.

Key Specifications

Pinout & Package

ICL7642ECPD+ is housed in a 14-pin plastic DIP (PD) package with standard dual-in-line footprint and through-hole mounting. Pin 1 is marked by a notch or dot; pin numbering follows counter-clockwise convention from top view.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad CMOS op amp applications.

Compared with TLV2474IDR and OPA4141AIDR, the ICL7642ECPD+ uniquely guarantees 1 pA input bias current across –40°C to +85°C while consuming only 10 μA per channel - making it irreplaceable in portable picoammeters and field-deployable pH analyzers where leakage-limited accuracy and battery life are co-constrained.

Availability

ICL7642ECPD+ is available at Aetrix Electronics and suitable for pH meter front-ends, photodiode transimpedance amplifiers, long-time constant integrators, and picoammeter input stages requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ICL7642ECPD+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for demanding industrial, medical, and instrumentation applications.

The ICL7642ECPD+ belongs to the ICL761X–ICL764X family - engineered specifically for ultra-low-input-current, low-power, wide-supply op amp applications in electrochemical, environmental, and scientific measurement systems.

FAQ

What is the guaranteed input bias current specification for ICL7642ECPD+ over its full operating temperature range?

The ICL7642ECPD+ guarantees a maximum input bias current of 4 nA at +125°C, with typical performance of 1 pA at +25°C. At its rated operating range of –40°C to +85°C, the datasheet specifies ≤500 pA for the E-grade version - validated across production lots and process corners. This makes ICL7642ECPD+ suitable for applications where input leakage must remain below 1 nA under worst-case thermal conditions.

Does ICL7642ECPD+ support rail-to-rail input common-mode voltage range?

No, the ICL7642ECPD+ does not support rail-to-rail input. Its common-mode voltage range is specified as –0.4 V to +0.6 V relative to the supplies (e.g., –4.0 V to +4.4 V at ±5 V). This limitation is inherent to its CMOS input stage design and distinguishes it from newer rail-to-rail input op amps. For applications requiring full-rail input, external level-shifting or alternative devices like the OPA4141 should be considered.

Can ICL7642ECPD+ be used in single-supply configurations with input signals near ground?

Yes, ICL7642ECPD+ operates reliably from a single 2V–16V supply. When referenced to ground (V− = GND), its input common-mode range extends down to –0.4 V - allowing inputs slightly below ground (e.g., –0.3 V) without phase reversal. However, inputs must stay within (V− – 0.3 V) to (V+ + 0.3 V), so for a 5 V single supply, valid input range is –0.3 V to +5.3 V. This supports grounded-sensor interfaces common in pH and gas sensing.

Is ICL7642ECPD+ internally compensated for unity-gain stability?

Yes, the ICL7642ECPD+ is internally compensated and stable at unity-gain configuration across its full operating range. Unlike the ICL7614 (which requires external compensation), the ICL7642 quad variant has no compensation pins and is qualified for AV = 1 operation without added capacitors - simplifying PCB layout and reducing BOM count in precision buffer and follower applications.

What is the maximum output current drive capability of ICL7642ECPD+ at ±5 V supply?

At ±5 V supply and 10 μA quiescent current, the ICL7642ECPD+ delivers ±1.5 mA output sink/source current into resistive loads. Drive capability scales with quiescent current: at 100 μA IQ, it provides ±5 mA; at 1 mA IQ, ±15 mA. These values are measured with output swing limited to ±4.8 V into 1 MΩ, ensuring linearity and avoiding thermal shutdown during sustained load conditions.