Analog Devices Inc./Maxim Integrated MAX4475AUA+T

Overview

MAX4475AUA+T from Maxim Integrated is a single-channel, rail-to-rail output, low-noise operational amplifier optimized for precision signal conditioning in single-supply systems. It delivers 10MHz gain-bandwidth, 0.0002% THD+N at 1kHz, 4.5nV/√Hz input voltage-noise density, and operates from +2.7V to +5.5V - making it ideal for high-fidelity ADC buffering and medical sensor front-ends.

For engineers reviewing the MAX4475AUA+T datasheet, MAX4475AUA+T pinout, MAX4475AUA+T application, or MAX4475AUA+T equivalent, this page provides verified circuit role, package mapping (8-pin µMAX), shutdown functionality, noise/distortion trade-offs, and validated alternative options for low-noise analog signal chains.

Technical Context

The MAX4475AUA+T is unity-gain stable with a 10MHz gain-bandwidth product and 3V/µs slew rate, supporting wideband closed-loop configurations down to AV = +1V/V. Its BiCMOS process enables ultra-low input bias current (1pA typ) and rail-to-rail output swing within 80mV of supplies into 1kΩ loads.

It features a dedicated SHDN pin that reduces quiescent current to 0.01µA and places the output in high-impedance state - critical for power-gated sensor interfaces. Input common-mode range extends to VSS − 0.1V and up to VDD − 1.7V, enabling ground-sensing operation without phase reversal.

Key Specifications

Pinout & Package

MAX4475AUA+T is housed in an 8-pin µMAX® package (package code U8+4), featuring exposed pad thermal enhancement and RoHS-compliant lead-free finish. The µMAX footprint (2.8mm × 3.0mm) offers 40% board area reduction versus SO-8 while maintaining SO-compatible pinout spacing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, rail-to-rail op amp applications.

Compared with OPA376AIDBVR and ADA4807-1ARMZ, the MAX4475AUA+T uniquely balances 10MHz bandwidth, 0.0002% THD+N, integrated shutdown, and true ground-sensing capability - making it the only option among the three qualified for battery-powered, precision DC-coupled medical and industrial sensor interfaces.

Availability

MAX4475AUA+T is available at Aetrix Electronics and suitable for medical instrumentation, portable test equipment, and high-resolution data acquisition systems requiring stable component supply across extended temperature ranges (−40°C to +125°C) and long production lifecycles.

Supply support for MAX4475AUA+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 demanding industrial, medical, and automotive applications.

The MAX4475AUA+T belongs to Maxim's low-noise, rail-to-rail op amp family engineered specifically for high-dynamic-range signal conditioning in space-constrained, low-power systems - emphasizing THD+N, input bias current, and supply voltage flexibility.

FAQ

What is the operating temperature range for the MAX4475AUA+T?

The MAX4475AUA+T is specified for operation from −40°C to +125°C. This extended industrial temperature range is validated across all key parameters including input offset voltage, THD+N, and output swing - ensuring reliability in medical devices, automotive subsystems, and outdoor instrumentation where ambient temperatures fluctuate widely. The µMAX package's thermal resistance (θ_JA = 206°C/W on multi-layer board) supports sustained operation at maximum junction temperature.

Does the MAX4475AUA+T support true rail-to-rail input operation?

No, the MAX4475AUA+T does not support rail-to-rail input. Its input common-mode voltage range extends from V_SS − 0.1V to V_DD − 1.7V, enabling ground-sensing capability but excluding the positive rail. However, its rail-to-rail output delivers V_OL ≤ 50mV and V_OH ≥ V_DD − 80mV into 1kΩ loads - critical for maximizing signal swing in low-voltage systems. This asymmetry is intentional for optimizing noise and distortion performance.

How does the shutdown feature of the MAX4475AUA+T affect output state?

When the SHDN pin is driven low (≤0.3×V_DD), the MAX4475AUA+T reduces quiescent supply current to 0.01µA and places the output in a high-impedance state - effectively disconnecting the amplifier from the load. This behavior prevents loading of downstream circuits during sleep mode and eliminates output leakage (±0.001µA max). The enable delay time from shutdown is 10µs to 0.1% settling, allowing rapid wake-up in responsive sensor systems.

Can the MAX4475AUA+T drive capacitive loads, and what is the limit?

Yes, the MAX4475AUA+T is stable driving capacitive loads up to 200pF without external compensation. This is confirmed by its capacitive-load stability specification and 70° phase margin at unity gain. For loads >100pF, feed-forward compensation (C_Z = 10 × R_F/R_G pF) is recommended when R_F||R_G > 20kΩ to preserve phase margin. Driving larger capacitive loads (e.g., cables or ADC inputs) may require isolation resistors or buffer staging to avoid peaking or oscillation.

What is the typical input offset voltage drift over temperature for the MAX4475AUA+T?

The MAX4475AUA+T has a typical input offset voltage drift (TCV_OS) of ±0.3µV/°C, with a maximum of ±6µV/°C over −40°C to +125°C. This low drift ensures minimal baseline shift in precision DC-coupled applications such as strain gauge bridges or thermopile amplifiers. At room temperature, V_OS is typically ±70µV and remains within ±750µV across the full temperature range - enabling accurate offset calibration with single-point correction in many systems.