Analog Devices Inc./Maxim Integrated MAX5400EKA+T

Overview

MAX5400EKA+T from Maxim Integrated is a 256-tap, 50kΩ digital potentiometer in an 8-pin SOT23 package, functioning as a digitally controlled variable resistor with midscale power-on reset, 5ppm/°C ratiometric temperature coefficient, and 0.1µA supply current at 2.7V - used for precision gain adjustment in programmable amplifiers and voltage reference trimming.

For engineers reviewing the MAX5400EKA+T datasheet, MAX5400EKA+T pinout, MAX5400EKA+T application, or MAX5400EKA+T equivalent, this page delivers verified electrical specs, SPI-compatible interface timing, wiper settling behavior, end-to-end resistance tolerance, and real-world circuit roles in adjustable I/V converters and noninverting amplifier feedback paths.

Technical Context

The MAX5400EKA+T implements a 255-resistor string between H and L terminals, with an 8-bit latch-controlled decoder selecting one of 256 tap points for the W terminal. It uses a write-only 3-wire SPI-compatible interface (CS/DIN/SCLK) with MSB-first serial loading and glitchless switching between taps.

Its internal POR circuit loads binary 128 at power-up to set the wiper to midscale (25kΩ from H or L). The device operates in two primary modes: voltage-divider (H–W–L) and variable-resistor (W connected to H or L), each with distinct INL/DNL specifications and tempco contributions.

Key Specifications

Pinout & Package

Package: 8-pin SOT23 (3mm × 3mm), surface-mount, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital potentiometer applications.

Compared with AD5241BRMZ50 and MCP41050-I/P, the MAX5400EKA+T offers superior thermal stability (5ppm/°C ratiometric vs. 35ppm/°C or uncharacterized), lowest quiescent current (0.1µA), and guaranteed midscale POR - making it optimal for precision, low-power, production-ready embedded calibration.

Availability

MAX5400EKA+T is available at Aetrix Electronics and suitable for programmable gain amplifiers, adjustable voltage references, and current-to-voltage converter calibration requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX5400EKA+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 high-performance analog and mixed-signal ICs for precision sensing, power management, and interface applications.

The MAX5400EKA+T belongs to Maxim's SOT-PoT™ digital potentiometer family, engineered for low-drift, low-power, space-constrained analog tuning in industrial and medical instrumentation.

FAQ

What is the guaranteed end-to-end resistance tolerance for MAX5400EKA+T?

The MAX5400EKA+T has a guaranteed end-to-end resistance of 50kΩ with ±25% tolerance (37.5kΩ to 62.5kΩ) over the full -40°C to +85°C temperature range, as specified in the Electrical Characteristics table under "End-to-End Resistance (RHL)".

Does MAX5400EKA+T support true SPI communication with bidirectional data flow?

No - the MAX5400EKA+T uses a write-only 3-wire serial interface compatible with SPI clocking conventions (CS/DIN/SCLK), but it lacks MISO functionality and does not support readback of wiper position or status registers.

Can MAX5400EKA+T operate from a 3.3V supply, and what is its typical supply current at that voltage?

Yes, MAX5400EKA+T operates from +2.7V to +5.5V. At VDD = 3.3V, its typical supply current is less than 1µA (measured at 0.7µA in typical operating characteristics), maintaining ultra-low power consumption in 3.3V systems.

What is the maximum recommended voltage across the H and L terminals of MAX5400EKA+T?

The absolute maximum voltage across H and L is limited by the Absolute Maximum Ratings: H and L must each stay within -0.3V to (VDD + 0.3V) relative to GND. Therefore, the maximum differential voltage is constrained to ≤ VDD + 0.6V, e.g., ≤5.8V at VDD = 5.5V.

How does the power-on reset (POR) function in MAX5400EKA+T, and is it user-controllable?

The MAX5400EKA+T POR automatically loads code 128 into the wiper latch at power-up, positioning the wiper at midscale (25kΩ from either H or L). This function is internal, non-maskable, and cannot be disabled or reconfigured - it ensures deterministic startup behavior without host initialization.