MAX5407EKA

Overview

The MAX5407EKA is a 32-tap audio logarithmic taper digital potentiometer in an 8-pin SOT-23 package. It features a fixed 20kΩ end-to-end resistance with a 35ppm/°C temperature coefficient and 1dB step resolution between taps. Operating on a single supply from +2.7V to +5.5V, it draws only 0.35µA in standby. The device includes zero-crossing detection to minimize audible switching noise and utilizes a simple 2-wire serial interface for wiper control.

Feature Summary

• 32-Tap Logarithmic Taper: Provides 1dB steps between tap positions for precise audio attenuation control.
• Zero-Crossing Detection: Minimizes audible clicks during wiper transitions by enabling changes only at signal zero crossings.
• Low Power Consumption: Operates with a standby supply current of 0.35µA and supports +2.7V to +5.5V single-supply operation.
• Compact Packaging: Available in a space-saving 8-pin SOT-23 package suitable for portable applications.

Applications

• Audio Volume Control
• Fading/Balancing Audio Signals
• Mechanical Potentiometer Replacement

Procurement Notes

Verify the component revision and manufacturer specifications against official Analog Devices documentation before integration. Confirm that the SOT-23-8 package dimensions and pinout align with the target PCB layout requirements. Ensure operating conditions remain within the specified -40°C to +85°C temperature range for reliable performance.

Selection Notes

Select this component for applications requiring digitally controlled audio attenuation with minimal power consumption. The 20kΩ resistance value and logarithmic taper are optimized for human ear perception in volume control circuits. Verify compatibility with the system's logic voltage levels, as the device interfaces with both +3V and +5V logic systems.

Part Context

The MAX5407 belongs to the Maxim Integrated SOT-PoT family of digital potentiometers. It serves as a solid-state alternative to mechanical potentiometers in audio equipment. The EKA suffix indicates the specific temperature range (-40°C to +85°C) and the SOT-23 package type.

Replacement Considerations

Direct replacements include other 32-tap digital potentiometers from the same family, such as the MAX5408 or MAX5409, which offer similar functionality but may differ in resistance values or taper characteristics. Ensure any substitute maintains the required logarithmic response and low-power specifications.

FAQ

How does the zero-crossing detection feature work?

When the ZCEN input is low, the device enables zero-crossing detection. This feature delays wiper position changes until the voltage at the L terminal matches the voltage at the H terminal, minimizing audible switching noise.

What is the default wiper position upon power-up?

The power-on reset feature sets the wiper to the maximum attenuation position (tap position 31, -31dB) when power is applied.

What is the resolution of the digital potentiometer?

The MAX5407 has 32 tap positions with a logarithmic taper, providing approximately 1dB steps between adjacent taps.