AD8403ARUZ50

Overview

The AD8403ARUZ50 is a quad-channel, 256-position digital potentiometer from Analog Devices. It operates on a single supply voltage ranging from 2.7 V to 5.5 V and features a nominal resistance of 50 kΩ with a temperature coefficient of 500 ppm/°C. The device utilizes an SPI-compatible 3-wire serial interface for data input and includes a serial output pin for daisy-chaining applications. Each channel contains a volatile latch that retains the wiper position until updated. The component is housed in a 24-lead Thin Shrink Small Outline Package (TSSOP) and is rated for operation across an extended industrial temperature range of −40°C to +125°C.

Feature Summary

• Quad-channel configuration with 256 tap positions per variable resistor
• SPI-compatible 3-wire serial interface with daisy-chain capability via SDO pin
• Power shutdown mode reduces current consumption to less than 5 μA
• Extended industrial temperature range from −40°C to +125°C

Applications

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

Procurement Notes

Verify the specific package variant, as the AD8403 family includes PDIP, SOIC, and TSSOP options. Confirm the resistance value suffix matches the required 50 kΩ specification. Check for automotive qualification requirements if the application demands AEC compliance, as standard versions may differ from qualified variants.

Selection Notes

Select this component when four independent digitally controlled resistors are needed in a compact surface-mount footprint. Ensure the system logic levels are compatible with the 2.7 V to 5.5 V operating range. Consider the volatile memory nature of the latches; implement external reset or power-on initialization routines if wiper position retention after power loss is required.

Part Context

This part belongs to the AD8400/AD8402/AD8403 family of digital potentiometers. The AD8403 specifically denotes the quad-channel version, distinguishing it from the single-channel AD8400 and dual-channel AD8402. All members share similar electrical characteristics and serial interface protocols but differ in channel count and package pinouts.

Replacement Considerations

Direct replacements within the same family include AD8403ARZ50 (SOIC package) or AD8403AN50 (PDIP package). Verify pin compatibility and thermal resistance differences when substituting between TSSOP, SOIC, and PDIP packages.

FAQ

How does the SHDN pin function?

The SHDN pin forces the resistor to an end-to-end open-circuit condition at Terminal A and shorts the wiper to Terminal B, achieving a microwatt power shutdown state while keeping the digital interface active.

What is the purpose of the SDO pin?

The Serial Data Output (SDO) pin allows simple daisy-chaining of multiple VR devices without additional external decoding logic by passing data through the serial register chain.

How is the device reset?

Asserting the RS (Reset) pin low forces the wiper to midscale by loading the value 80H into the VR latch.