MAX5400EKA+T

Overview

The MAX5400EKA+T is a 256-tap digitally controlled variable resistor housed in an 8-pin SOT23 package. It operates on a single supply voltage ranging from +2.7V to +5.5V with an ultra-low supply current of 0.1µA at VDD = 2.7V. The device features a nominal end-to-end resistance of 50kΩ, a ratiometric temperature coefficient of 5ppm/°C, and a power-on reset that initializes the wiper to midscale (position 128). It supports glitchless switching between taps and utilizes a 3-wire SPI-compatible serial interface for control.

Feature Summary

• 256-tap resolution with 50kΩ end-to-end resistance
• Ultra-low 0.1µA supply current at 2.7V operation
• Glitchless switching and power-on reset to midscale
• 3-wire SPI-compatible digital interface

Applications

• Mechanical potentiometer replacement
• Low-drift programmable gain amplifiers (PGAs)
• Adjustable voltage references

Procurement Notes

Verify the 'EKA' suffix corresponds to the 8-pin SOT23 package and the '+T' indicates tape-and-reel packaging. Confirm the '+T' suffix denotes lead-free compliance as per standard Maxim Integrated conventions. Ensure the component meets the extended industrial temperature range of -40°C to +85°C.

Selection Notes

Select the MAX5400 variant for a 50kΩ nominal resistance or the MAX5401 for 100kΩ. Both share identical pinouts and electrical characteristics except for resistance values. The MAX5400EKA+T is suitable for low-power applications requiring precise digital adjustment of resistance or voltage division ratios.

Part Context

The MAX5400EKA+T belongs to the MAX5400/MAX5401 family of SOT-PoT™ digital potentiometers. This series provides mechanically equivalent functionality in a compact solid-state form factor, designed to replace traditional mechanical pots in space-constrained designs requiring digital control.

Replacement Considerations

The MAX5401EKA+T serves as a direct functional substitute with identical pinout and specifications, differing only in nominal end-to-end resistance (100kΩ vs. 50kΩ). No other cross-model replacements are documented in the provided datasheet.

FAQ

What is the default wiper position upon power-up?

The internal power-on reset circuitry sets the wiper to the midscale position, corresponding to code 128.

How does the device handle switching between resistor taps?

The MAX5400EKA+T provides glitchless switching between resistor taps to prevent output transients during state changes.

What is the maximum continuous current allowed into pins H, L, and W?

The absolute maximum rating specifies a continuous current limit of ±1mA into pins H, L, and W.