Analog Devices Inc./Maxim Integrated MAX40056FAUA+T

Overview

The MAX40056FAUA+T from Maxim Integrated is a bidirectional current-sense amplifier optimized for PWM-driven inductive loads, featuring -0.1V to +65V input common-mode range, 50V/V fixed gain, ±5µV typical input offset voltage, and 300kHz bandwidth. It enables precise phase-current monitoring in motor control systems with integrated overcurrent detection via window comparator.

For engineers reviewing the MAX40056FAUA+T datasheet, MAX40056FAUA+T pinout, MAX40056FAUA+T application, or MAX40056FAUA+T equivalent, this page delivers verified specifications, validated pin functions, confirmed automotive-grade AEC-Q100 qualification, real-world motor/solenoid use cases, and two technically documented alternative parts with explicit functional and packaging differences.

Technical Context

The MAX40056FAUA+T employs a chopper-stabilized architecture to achieve ±5µV (typ) input offset and <0.05% (typ) gain error across -40°C to +125°C, enabling accurate low-value shunt measurements. Its proprietary PWM-rejection input stage recovers from ±500V/µs edges in 500ns while maintaining 60dB AC CMRR at 50V common-mode with fast slew.

It integrates a 1.5V ±1% internal reference (1.485V–1.515V) that offsets the rail-to-rail output to indicate current direction, and supports external reference override above 1.65V. The built-in window comparator uses REF and CIP inputs to generate active-low COP fault signals for both over- and under-current conditions.

Key Specifications

Pinout & Package

MAX40056FAUA+T is packaged in an 8-pin µMAX (U8+4) measuring 3.0mm × 3.0mm × 0.95mm, with exposed pad for thermal enhancement and RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional current-sense amplifier applications.

Compared with INA240A1QDRQ1 and MAX40057FAUA+T, the MAX40056FAUA+T uniquely combines 50V/V gain, integrated 1.5V reference with load capability, and dual-threshold comparator in the compact µMAX package-making it optimal for space-constrained, high-accuracy motor phase sensing where fault response time and BOM simplification are critical.

Availability

MAX40056FAUA+T is available at Aetrix Electronics and suitable for automotive EPS systems, industrial servo amplifiers, and 48V battery management applications requiring stable component supply, long-term lifecycle support, and AEC-Q100 compliance.

Supply support for MAX40056FAUA+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 automotive, industrial, and communications markets, with emphasis on high-reliability, low-power, and noise-immune solutions.

The MAX40056 family was developed specifically for high-fidelity current sensing in PWM-controlled inductive loads, addressing the need for fast recovery, wide common-mode range, and integrated fault detection in next-generation motor drives and solenoid controllers.

FAQ

What is the gain configuration of the MAX40056FAUA+T?

The MAX40056FAUA+T has a fixed gain of 50V/V, as indicated by the "F" suffix in the part number per Maxim's ordering guide. This gain is laser-trimmed at wafer test and remains stable across temperature (-40°C to +125°C) with ≤0.5% error. It defines the input differential sense range as ±30mV at 3.3V supply with internal 1.5V reference, enabling high-resolution measurement with low-value shunt resistors. No external gain-setting components are required for the MAX40056FAUA+T.

Does the MAX40056FAUA+T support external reference override?

Yes, the MAX40056FAUA+T supports external reference override: when a voltage >1.65V is applied to the REF pin, the internal 1.5V reference is automatically disabled and the external voltage becomes the new output common-mode point. This allows scaling the full-scale output swing-for example, using a 2.5V reference with 5V supply extends the input sense range to ±50mV. The REF pin can sink or source up to 500µA while maintaining ≤70µV/µA load regulation, as specified in the Electrical Characteristics table.

How does the integrated window comparator in the MAX40056FAUA+T operate?

The MAX40056FAUA+T's window comparator monitors the OUT voltage against two thresholds: a user-defined lower threshold (VCIP) set by a resistor divider from REF, and an internally generated upper threshold (VA = 2×VREF − VCIP). When OUT falls below VCIP or rises above VA, the COP pin asserts low. Hysteresis of 40mV prevents chatter near thresholds. Propagation delay is 12µs (high-to-low) and 14µs (low-to-high), enabling sub-20µs fault response-critical for protecting IGBTs and MOSFETs in motor drives.

Is the MAX40056FAUA+T qualified for automotive applications?

Yes, the MAX40056FAUA+T is AEC-Q100 Grade 1 qualified (−40°C to +125°C ambient), with full characterization across temperature and supply voltage. It meets automotive reliability requirements including HTOL, TC, and ESD testing per AEC standards. The µMAX package (U8+4) is automotive-grade with qualified assembly sites and lot traceability. Its -5V to +70V input protection and 500ns PWM recovery make it suitable for EPS, HVAC actuators, and transmission solenoids where electrical stress and thermal cycling are severe.

What layout considerations are critical for optimal performance of the MAX40056FAUA+T?

Optimal MAX40056FAUA+T performance requires strict Kelvin routing: RS+ and RS- traces must connect directly to opposite ends of the shunt resistor with separate force-and-sense vias, minimizing parasitic resistance. A solid ground plane beneath the µMAX package (with thermal pad soldered to ≥4 thermal vias) is mandatory for thermal stability and noise rejection. Bypass capacitors (10nF COG + 1µF X5R) must be placed within 2mm of VDD and GND pins. REF and OUT traces should avoid noisy digital or power planes to preserve 140dB DC CMRR.