Analog Devices Inc./Maxim Integrated ICL7612DESA+T

Overview

ICL7612DESA+T from Maxim Integrated is a single-channel, ultra-low-input-bias-current CMOS operational amplifier with programmable quiescent current (10 μA/100 μA/1 mA), extended common-mode voltage range (±5.3 V at 10 μA), and 1 pA typical input bias current - optimized for pH meters, photodiode amplifiers, and picoammeters requiring femtoamp-level leakage control.

For engineers reviewing the ICL7612DESA+T datasheet, ICL7612DESA+T pinout, ICL7612DESA+T application, or ICL7612DESA+T equivalent, this device delivers verified low-noise current (0.01 pA/√Hz), 10¹² Ω input impedance, ±1 V to ±8 V dual-supply operation, and temperature-stable performance across –40°C to +85°C in an 8-pin SOIC package.

Technical Context

The ICL7612DESA+T implements a monolithic CMOS architecture with externally selectable quiescent current via the IOSET pin, enabling trade-offs between power (10 μA min) and bandwidth (up to 1.4 MHz GBW at 1 mA). Its extended common-mode input range (–5.3 V to +5.3 V with V_S = ±5 V) supports rail-to-rail sensing in high-impedance source configurations.

Offset nulling is supported via dedicated OFFSET pins using a 25 kΩ potentiometer tied to V+, and the device is internally compensated for unity-gain stability - eliminating external compensation components required by variants like the ICL7614.

Key Specifications

Pinout & Package

ICL7612DESA+T is housed in an 8-pin Small Outline (SO) package (SA code), surface-mount, JEDEC MS-012AC compliant, with 1.27 mm pitch and 4.9 mm × 6.0 mm body size.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-bias-current op-amp applications.

Compared with LTC1050CS8#PBF and TLC27L2CDR, the ICL7612DESA+T uniquely combines programmable IQ, extended CMVR, and 1 pA I_B in a single SOIC package - making it the only option among the three that supports both ultra-low-leakage DC sensing and battery-life-optimized operation across –40°C to +85°C.

Availability

ICL7612DESA+T is available at Aetrix Electronics and suitable for pH meter front-ends, photodiode transimpedance amplifiers, and picoammeter cores requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for ICL7612DESA+T 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, mixed-signal, and power-management ICs for industrial, medical, and communications systems.

The ICL761X family was engineered specifically for ultra-high-impedance, low-power signal conditioning - targeting applications where input bias current, noise, and supply flexibility outweigh raw speed requirements.

FAQ

What is the maximum supply voltage for the ICL7612DESA+T?

The ICL7612DESA+T supports a total supply voltage (V+ to V–) of up to +18 V. This allows operation from ±1 V to ±8 V dual supplies or 2 V to 16 V single supplies. Absolute maximum ratings must not be exceeded - sustained operation above ±8 V requires verification of power dissipation and thermal derating per the datasheet's derating curves. The ICL7612DESA+T maintains specified performance across its full rated supply range.

How do I configure the quiescent current on the ICL7612DESA+T?

The ICL7612DESA+T uses the IOSET pin (Pin 5) to select quiescent current: tie to V+ for 10 μA, leave floating (or connect to mid-supply via resistor divider) for 100 μA, or tie to V– for 1 mA. These settings directly scale unity-gain bandwidth (0.044 MHz to 1.4 MHz) and slew rate (0.016 V/µs to 1.6 V/µs). The ICL7612DESA+T does not require external resistors - configuration is purely voltage-level based.

Does the ICL7612DESA+T require external frequency compensation?

No, the ICL7612DESA+T is internally compensated for unity-gain stability and requires no external capacitor. This distinguishes it from the ICL7614 variant, which uses external compensation. The ICL7612DESA+T's internal compensation ensures predictable phase margin and step response across all IQ settings and load conditions without added components - simplifying design for low-frequency precision applications.

What is the guaranteed input bias current specification for ICL7612DESA+T over temperature?

The ICL7612DESA+T guarantees input bias current ≤4 nA over the full operating temperature range of –40°C to +85°C. At +25°C, typical I_B is 1 pA, with a maximum of 50 pA. The 4 nA limit ensures predictable leakage error in high-impedance circuits even under worst-case thermal stress - critical for pH meter calibration stability and picoammeter accuracy.

Can the ICL7612DESA+T drive a 10 kΩ load while maintaining rail-to-rail output swing?

Yes, the ICL7612DESA+T delivers ±4.0 V output swing into a 10 kΩ load at ±5 V supplies when configured for 1 mA quiescent current. At lower IQ settings (10 μA or 100 μA), output swing degrades to ±4.8 V and ±4.5 V respectively into 100 kΩ and 1 MΩ loads. For 10 kΩ drive at low IQ, external buffering is recommended. The ICL7612DESA+T's CMOS output stage ensures millivolt-level proximity to rails under light loads.