AD8402AN1

Overview

The AD8402AN1 is a dual-channel, 8-bit digital potentiometer manufactured by Analog Devices Inc. It features two independent variable resistors with 256 tap positions and linear taper characteristics. The device operates on a single supply voltage ranging from 2.7 V to 5.5 V and utilizes a 3-wire SPI-compatible serial interface for data input. Total resistance values are available in 1 kΩ, 10 kΩ, 50 kΩ, and 100 kΩ options. The component employs volatile memory, requiring power restoration to maintain settings, and supports an update data loading rate of up to 10 MHz.

Feature Summary

• Dual-channel configuration with 256-position variable resistance
• SPI-compatible 3-wire serial interface supporting 10 MHz update rates
• Single-supply operation between 2.7 V and 5.5 V
• Power shutdown current less than 5 μA

Applications

• Mechanical potentiometer replacement
• Programmable filters, delays, and time constants
• Volume control and panning systems
• Line impedance matching
• Power supply adjustment

Procurement Notes

Verify the specific total resistance value (1 kΩ, 10 kΩ, 50 kΩ, or 100 kΩ) as the base model number does not indicate the resistor tolerance or value suffix. Confirm package availability, as the 'AN' designation typically refers to a PDIP package, but verify against current manufacturer stock lists due to potential discontinuation status associated with older revisions.

Selection Notes

Select this component when replacing mechanical potentiometers in space-constrained designs requiring digital control. Ensure the system can tolerate volatile memory behavior if power loss occurs. Verify that the required resistance value matches the specific suffix code, as the base part number covers multiple resistance variants. Check compatibility with the host microcontroller's SPI voltage levels given the 2.7 V minimum operating threshold.

Part Context

The AD8402 belongs to the AD8400/AD8402/AD8403 family of digitally controlled variable resistors. These devices function electronically like mechanical potentiometers but offer programmability via serial interfaces. The AD8402 specifically provides dual channels in a compact package, serving as a direct drop-in replacement for analog trimmers in applications such as gain control and bias adjustment.

Replacement Considerations

Direct substitutes include other dual-channel digital potentiometers from Analog Devices such as the AD8403 (quad channel) or AD8400 (single channel) if pin counts allow adaptation. Cross-vendor replacements require verifying SPI protocol compatibility and ensuring equivalent resistance ranges and tap resolutions.