Analog Devices Inc./Maxim Integrated ICL7612DCSA-T

Overview

ICL7612DCSA-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 operating from ±1 V to ±8 V supplies.

For engineers reviewing the ICL7612DCSA-T datasheet, ICL7612DCSA-T pinout, ICL7612DCSA-T application, or ICL7612DCSA-T equivalent, this device delivers verified low-noise current (0.01 pA/√Hz), 10¹² Ω input impedance, and rail-to-rail output swing within millivolts of supply rails - critical for high-impedance sensor interfacing and precision integrator designs.

Technical Context

The ICL7612DCSA-T implements a monolithic CMOS architecture with pin-selectable quiescent current via the IOSET terminal, enabling trade-offs between power (10 μA min) and performance (1.4 MHz GBW at 1 mA). Its extended common-mode input range (–5.1 V to +5.3 V at IQ = 100 μA) supports operation near negative rail - a key differentiator versus standard ICL7611/7616 variants.

It features internal unity-gain compensation, offset null capability via dedicated OFFSET pins, and CMOS output stage delivering ±4.8 V swing into 1 MΩ at ±5 V supply. Input bias current remains ≤400 pA over 0°C to +70°C - validated across temperature and supply voltage variations per datasheet Tables 1–3.

Key Specifications

Pinout & Package

ICL7612DCSA-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 ICL7612DCSA-T uniquely combines programmable IQ, extended CMVR down to V– – 0.3 V, and 1 pA bias current in an SO-8 package - making it the only option among the three that supports both battery-powered pH meters and precision picoammeters without design compromise.

Availability

ICL7612DCSA-T is available at Aetrix Electronics and suitable for pH meter front-ends, photodiode transimpedance amplifiers, picoammeters, and low-droop sample/hold circuits requiring stable component supply across industrial and medical OEM programs.

Supply support for ICL7612DCSA-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 and mixed-signal ICs for demanding industrial, medical, and automotive applications - emphasizing low-power, high-accuracy, and robust performance.

The ICL761X family was engineered specifically for ultra-high-impedance sensor interfacing and low-leakage precision amplification - targeting applications where input bias current, noise, and common-mode range directly impact measurement fidelity.

FAQ

What is the guaranteed maximum input bias current for ICL7612DCSA-T over its full operating temperature range?

The ICL7612DCSA-T guarantees input bias current ≤400 pA over the 0°C to +70°C operating temperature range (C-grade), as specified in Table 1 of the datasheet. At +125°C (M-grade), max IB rises to 4 nA - but ICL7612DCSA-T is rated only for 0°C to +70°C per its SA package suffix and ordering code DCSA.

Can ICL7612DCSA-T operate from a single +5 V supply while accepting input signals down to 0 V?

Yes. With IQ set to 100 μA, the ICL7612DCSA-T supports a common-mode input range from –5.1 V to +5.3 V relative to its supplies. When powered from +5 V and GND (i.e., V+ = +5 V, V– = 0 V), this translates to 0 V to +5.3 V - allowing 0 V-referenced inputs without phase reversal or clipping.

How is quiescent current selected on ICL7612DCSA-T, and what are the valid voltage levels for each setting?

Quiescent current on ICL7612DCSA-T is set via the IOSET pin (Pin 7): 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 states are explicitly defined in the "Detailed Description" section and validated across supply voltages from ±1 V to ±8 V.

Does ICL7612DCSA-T require external frequency compensation, and is it unity-gain stable?

No. The ICL7612DCSA-T is internally compensated and unity-gain stable - unlike the ICL7614, which requires external capacitor compensation. This is confirmed in the "Frequency Compensation" subsection and applies to all ICL7612 variants regardless of VOS grade or package.

What is the maximum load capacitance ICL7612DCSA-T can drive without instability when configured as a unity-gain buffer?

The ICL7612DCSA-T can safely drive up to 100 pF capacitive load in unity-gain configuration, as demonstrated in the "Voltage Follower Large Signal Pulse Response" test waveforms (Figures 19–21). For loads >100 pF, a series isolation resistor (e.g., 100 Ω) is recommended to maintain phase margin.