AD8402ARUZ100

Overview

The AD8402ARUZ100 is a dual-channel, 256-position digital potentiometer from Analog Devices Inc. It operates on a single 2.7 V to 5.5 V supply and features an SPI-compatible serial interface for data loading at rates up to 10 MHz. The device provides two independent variable resistors with a nominal resistance of 100 kΩ and a linear taper. Each channel includes volatile memory to retain settings until updated. Key control pins include Chip Select (CS), Serial Data In (SDI), Clock (CLK), Reset (RS), and Shutdown (SHDN). The component is housed in a 14-lead TSSOP package and supports operation across the extended industrial temperature range of −40°C to +125°C.

Feature Summary

• Dual-channel architecture with 256 programmable tap positions per resistor
• SPI-compatible 3-wire serial interface supporting daisy-chaining via SDO
• Power shutdown mode reduces current consumption to less than 5 μA
• Active-low Reset pin forces wiper to midscale (80H code)
• Nominal resistance tolerance of ±1% between channels

Applications

• Mechanical potentiometer replacement in space-constrained designs
• Programmable filters, delays, and time constant adjustments
• Line impedance matching and power supply voltage trimming

Procurement Notes

Verify the specific suffix 'U' indicates the TSSOP-14 package variant rather than the standard SOIC-14. Confirm that the 'Z' designation aligns with RoHS compliance requirements for the target assembly process. Ensure the 100 kΩ resistance value matches the circuit design constraints before procurement.

Selection Notes

Select this model when a dual-channel configuration is required within a compact surface-mount footprint. The 100 kΩ nominal resistance offers a bandwidth of approximately 71 kHz. Consider the volatile memory nature of the device; if non-volatile retention is necessary, external storage logic must be implemented to preserve settings during power loss.

Part Context

This component belongs to the AD840x family, which also includes the single-channel AD8400 and the quad-channel AD8403. While sharing identical electrical characteristics and serial protocols, the AD8402 specifically integrates two variable resistors into a 14-lead package, optimizing board space compared to utilizing separate single-channel units.

Replacement Considerations

Direct functional equivalents within the same package include the AD8402AR10 (10 kΩ) and AD8402ARU50Z (50 kΩ). Cross-model replacements like the AD8403 require adapting to a 24-lead package.