Analog Devices Inc. AD8403ARUZ100

Overview

AD8403ARUZ100 from Analog Devices is a quad-channel, 256-position digital potentiometer in a 24-lead TSSOP package, offering 100 kΩ nominal end-to-end resistance, ±1% channel-to-channel matching, and SPI-compatible 3-wire serial interface. It operates from 2.7 V to 5.5 V, supports −40°C to +125°C, and delivers microwatt shutdown (<5 μA) for precision analog adjustment in programmable gain, filter tuning, and bias control.

For engineers reviewing the AD8403ARUZ100 datasheet, AD8403ARUZ100 pinout, AD8403ARUZ100 application, or AD8403ARUZ100 equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed automotive-grade performance, and two rigorously cross-checked alternative parts with documented functional and application differences.

Technical Context

The AD8403ARUZ100 implements four independent 8-bit resistor ladders, each with dedicated A/B/W terminals and individual address decoding (A1/A0) via a 10-bit serial word (2 address + 8 data bits). Its wiper position is updated synchronously on CLK rising edge under active CS, with SDO enabling daisy-chaining across multiple devices without external logic.

Each channel features a fixed 100 kΩ resistor (±30% tolerance per Table 2), 500 ppm/°C tempco, and monotonic 8-bit rheostat/potentiometer operation. The SHDN pin forces A-terminal open-circuit and shorts W to B, achieving <5 μA shutdown current while preserving latch state for instant resumption.

Key Specifications

Pinout & Package

AD8403ARUZ100 uses a 24-lead TSSOP (RU-24) package, 4.4 mm × 7.8 mm, 1.1 mm profile, optimized for space-constrained PCBs including PCMCIA and portable instrumentation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital potentiometer applications.

Compared with MAX5487ETE+ and AD5204BRUZ100, AD8403ARUZ100 uniquely combines quad integration, guaranteed monotonic 8-bit performance, daisy-chain SDO, and automotive temperature range in a single RU-24 package-reducing component count, layout complexity, and qualification effort for multi-channel analog tuning.

Availability

AD8403ARUZ100 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial sensor calibration modules, and programmable filter designs requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability.

Supply support for AD8403ARUZ100 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Wilmington, MA.

The AD8400/AD8402/AD8403 family was designed specifically for replacing mechanical potentiometers in demanding environments-delivering robust SPI-controlled resistance adjustment with automotive-grade temperature range, low power shutdown, and tight channel matching for precision analog systems.

FAQ

What is the maximum operating voltage across the A-B terminals of the AD8403ARUZ100?

The AD8403ARUZ100 supports a maximum voltage of VDD across any two terminals (A, B, or W), with VDD rated from 2.7 V to 5.5 V. Absolute maximum ratings specify VA, VB, VW to GND as 0 V to VDD, and VDD to GND as −0.3 V to +8 V. Exceeding these limits risks permanent damage. For reliable operation, keep A-B differential voltage ≤ VDD and ensure current stays within ±540 μA continuous for 100 kΩ channels.

Does the AD8403ARUZ100 support true daisy-chaining, and how is it implemented?

Yes, the AD8403ARUZ100 supports true daisy-chaining via its SDO (Serial Data Out) pin (Pin 13). When multiple AD8403ARUZ100 devices are connected, SDI of Device N+1 connects to SDO of Device N. A 10-bit serial word shifts through the chain; each device decodes its own address bits (A1,A0) and loads the subsequent 8 data bits into its latch. This eliminates external decoding logic and enables synchronized updates across all devices using a single SPI bus.

How does the shutdown function affect wiper position retention in the AD8403ARUZ100?

When SHDN (Pin 10) is pulled low, the AD8403ARUZ100 forces each channel's A-terminal into open-circuit and shorts its wiper (W) to B-terminal, drawing <5 μA total supply current. Crucially, the internal VR latches retain their last loaded 8-bit code. Upon returning SHDN high, the wiper immediately resumes the exact resistance position prior to shutdown-no reinitialization or communication required.

What is the guaranteed monotonicity specification for the AD8403ARUZ100, and where is it documented?

The AD8403ARUZ100 guarantees monotonic operation across all 256 steps, with Differential Nonlinearity (DNL) bounded to ±1 LSB maximum for 10 kΩ and 50 kΩ/100 kΩ versions (Table 1 and Table 2, Rev. E datasheet). This ensures no missing codes or step reversals during wiper traversal-critical for closed-loop control. Monotonicity is explicitly stated in footnotes to Tables 1 and 2 and confirmed in the General Description section.

Can the AD8403ARUZ100 be used in a 3-wire rheostat configuration, and what are the terminal connections?

Yes, the AD8403ARUZ100 supports 3-wire rheostat mode. For each channel, connect Terminal A to the input signal, Terminal B to system ground (or fixed reference), and use Terminal W as the adjustable output node. Leave the unused terminal (e.g., B if using A-W) unconnected. This configuration provides variable resistance between A and W, with wiper position controlled digitally. All four channels operate independently in this mode.