Analog Devices Inc./Maxim Integrated MAX4461UESA

Overview

MAX4461UESA from Maxim Integrated is a fixed-gain (G = 1 V/V), rail-to-rail output instrumentation amplifier optimized for precision low-level differential signal amplification in single-supply systems. It features ±0.1% gain accuracy, 100 µV input offset voltage, 1 pA typical input bias current, and operates from 2.85V to 5.25V with 700 µA quiescent current. It is used in industrial strain-gauge interfaces and low-side current sensing where ground-referenced unipolar output and high CMRR are required.

For engineers reviewing the MAX4461UESA datasheet, MAX4461UESA pinout, MAX4461UESA application, or MAX4461UESA equivalent, key selection criteria include its factory-trimmed unity gain, shutdown control (SHDN), SO-8 package compatibility, and guaranteed performance over –40°C to +85°C with rail-to-rail output swing referenced to GND.

Technical Context

The MAX4461UESA implements Maxim's proprietary indirect current-feedback architecture, enabling ground-sensing capability while maintaining ultra-low input bias current and enhanced common-mode rejection. Its internal transconductance stages convert differential input voltage and output feedback into precision currents, subtracted and amplified by a high-gain loop amplifier with Class AB output stage.

This architecture delivers 2.5 MHz gain-bandwidth product, 90 dB minimum CMRR (up to 120 dB typ), and 80 dB PSRR across supply range - all while supporting true rail-to-rail output swing on a single 2.85V–5.25V supply. The SHDN pin enables logic-controlled power-down to <1 µA, with high-impedance output during shutdown.

Key Specifications

Pinout & Package

MAX4461UESA is housed in an 8-pin SO (Small Outline) package with standard 1.27 mm pitch and gull-wing leads. Pin 1 is marked by a beveled corner or dot; the package is RoHS-compliant and rated for surface-mount reflow.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar instrumentation amplifier applications.

Compared with AD8221ARMZ and INA333AIDR, MAX4461UESA uniquely combines factory-trimmed unity gain, integrated shutdown, ground-sensing operation, and rail-to-rail output in an SO-8 package - making it optimal for cost-sensitive, space-constrained industrial and medical designs requiring minimal external components and deterministic performance.

Availability

MAX4461UESA is available at Aetrix Electronics and suitable for industrial process control, precision low-side current sense, and battery-powered medical equipment requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX4461UESA 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 applications.

The MAX4460/MAX4461/MAX4462 family was engineered specifically for low-power, single-supply instrumentation amplifier applications demanding ground-sensing capability, ultra-low input bias current, and high accuracy without external gain components.

FAQ

What is the gain configuration of MAX4461UESA?

The MAX4461UESA is factory-trimmed to a fixed gain of 1 V/V (unity gain), denoted by the "U" suffix in its ordering code. This eliminates the need for external gain-setting resistors and guarantees ±0.1% gain accuracy at +25°C. Gain cannot be adjusted externally - unlike the MAX4460, which uses an FB pin for programmable gain. The MAX4461UESA's fixed gain simplifies layout and improves temperature stability in precision measurement circuits.

Does MAX4461UESA support true rail-to-rail output swing?

Yes, MAX4461UESA delivers rail-to-rail output swing from GND to VDD under light-load conditions (≥20 kΩ). At 5V supply, output typically swings within 4 mV of GND and 8 mV of VDD (RL = 20 kΩ). Performance degrades slightly under heavier loads or at temperature extremes, but the device maintains usable swing across its full –40°C to +85°C operating range. This feature maximizes dynamic range when interfacing with 12-bit or higher ADCs.

How does the SHDN pin function on MAX4461UESA?

The SHDN pin on MAX4461UESA is a logic-controlled shutdown input: drive it high (≥0.7 × VDD) for normal operation; pull it low (≤0.3 × VDD) to enter shutdown mode, reducing supply current to <1 µA. During shutdown, the output goes high-impedance (>100 kΩ), and internal transconductance stages are disabled. External feedback networks remain connected, so output behavior under load depends on external circuitry - e.g., it may settle near GND if loaded to ground.

What is the input common-mode voltage range for MAX4461UESA?

The input common-mode voltage range for MAX4461UESA is specified from –0.1 V to (VDD – 1.7 V) at +25°C, and –0.1 V to (VDD – 1.85 V) over full temperature range. This ground-sensing capability allows accurate amplification of differential signals whose common-mode level is near GND - essential for low-side current sensing and bridge-based transducers. The range is independent of gain setting and applies to both IN+ and IN– inputs.

Can MAX4461UESA operate from a 3.3V supply?

Yes, MAX4461UESA is fully specified for operation from 2.85V to 5.25V, including standard 3.3V systems. At 3.3V, it maintains 700 µA typical supply current, 100 µV typical offset, and rail-to-rail output swing (within 0.25 mV of rails at RL = 200 kΩ). The 2.85V minimum ensures compatibility with partially discharged Li-ion batteries or LDOs with tight dropout, making it suitable for portable and energy-conscious designs.