AD8403AR100

Overview

The AD8403AR100 is a quad-channel, 256-position digitally controlled variable resistor (VR) from Analog Devices. It operates on a single 2.7 V to 5.5 V supply and features an SPI-compatible 3-wire serial interface with a 10 MHz update rate. Each channel provides a programmable resistance between 0 Ω and 100 kΩ with linear tapering. The device includes power shutdown capability drawing less than 5 μA, a reset pin for midscale positioning, and daisy-chaining support via SDO. It functions within an extended industrial temperature range of −40°C to +125°C.

Feature Summary

• Quad-channel architecture with 256 tap positions per channel
• SPI-compatible 3-wire serial interface supporting 10 MHz clock rates
• Power shutdown mode reduces current consumption below 5 μA
• Daisy-chain capability through dedicated Serial Data Output (SDO) pin

Applications

• Mechanical potentiometer replacement in embedded systems
• Programmable filters, delays, and time constant adjustments
• Volume control and audio panning circuits
• Line impedance matching applications

Procurement Notes

Verify the specific suffix 'AR100' against the manufacturer's ordering guide to confirm the 100 kΩ resistance value and SOIC-24 package type. Confirm RoHS compliance status and check for automotive qualification requirements if operating in harsh environments. Ensure the design accounts for the volatile memory nature of the wiper settings upon power loss.

Selection Notes

Select this component when four independent variable resistors are required in a compact surface-mount footprint. The 100 kΩ nominal resistance suits high-impedance signal paths. Consider the 500 ppm/°C temperature coefficient for thermal stability needs. Verify that the system logic levels align with the 2.7 V to 5.5 V input requirements for CS, SDI, and CLK signals.

Part Context

This part belongs to the AD8400 family, which also includes the single-channel AD8400 and dual-channel AD8402. All variants share identical electrical characteristics and serial interface protocols but differ in channel count and physical package dimensions. The AD8403 specifically utilizes a 24-lead SOIC package to accommodate the four independent variable resistors.

Replacement Considerations

Direct functional replacements include other quad-channel digital potentiometers from Analog Devices such as the AD5253, though the AD5253 uses I2C instead of SPI and offers nonvolatile memory. Cross-vendor alternatives must be evaluated for pin compatibility, serial protocol differences, and resistance tolerance specifications.