Analog Devices Inc. AD5242BRU100

Overview

AD5242BRU100 from Analog Devices is a dual-channel, I²C-compatible 256-position digital potentiometer with 100 kΩ end-to-end resistance, ±1% channel-to-channel matching, 30 ppm/°C temperature coefficient, and operation from 2.7 V to 5.5 V single supply or ±2.7 V dual supply. It serves as a programmable resistor in precision gain/offset adjustment circuits for instrumentation and audio signal conditioning.

For engineers reviewing the AD5242BRU100 datasheet, AD5242BRU100 pinout, AD5242BRU100 application, or AD5242BRU100 equivalent, key selection criteria include its dual-channel architecture, I²C readback capability, programmable logic outputs O1/O2, shutdown function via SHDN pin or SD bit, and guaranteed −40°C to +105°C operation in 16-lead TSSOP package.

Technical Context

The AD5242BRU100 implements two independent 8-bit digitally controlled resistor ladders (RDAC1/RDAC2), each with 256 tap points between A–W–B terminals. Its internal power-on reset defaults both wipers to midscale (code 0x80), and wiper position is updated via I²C address byte (7-bit, configurable via AD0/AD1 pins), instruction byte (A/B subaddress select, SD shutdown bit, RS midscale reset, O1/O2 control), and data byte.

It supports both rheostat (A–W or B–W) and potentiometer divider (A–W–B) modes. In divider mode, output voltage drift is reduced to 5 ppm/°C due to ratio-metric operation, while rheostat mode maintains 30 ppm/°C RAB drift. The device includes two push-pull logic outputs (O1/O2) capable of sourcing/sinking ≥1.6 mA, and an active-low SHDN pin that disconnects A and shorts W to B without altering register contents.

Key Specifications

Pinout & Package

AD5242BRU100 is housed in a 16-lead TSSOP package (body width 4.4 mm, lead pitch 0.65 mm), optimized for high-density PCB layouts and thermal performance (θJA = 180°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5242BRU10 and MAX5487ETE+, the AD5242BRU100 uniquely balances dual-channel precision, I²C simplicity, and 100 kΩ impedance for DC-coupled calibration and audio applications-offering superior channel matching and integrated logic outputs not found in alternatives.

Availability

AD5242BRU100 is available at Aetrix Electronics and suitable for instrumentation calibration, audio volume control, and programmable reference generation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD5242BRU100 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD5242BRU100 belongs to Analog Devices' precision digital potentiometer product line, engineered for replacing mechanical trimmers in automated calibration, sensor signal conditioning, and programmable analog front-ends where reliability and temperature stability are critical.

FAQ

What is the maximum operating temperature range for the AD5242BRU100?

The AD5242BRU100 is fully specified and guaranteed to operate from −40°C to +105°C. This extended temperature range is validated per the Absolute Maximum Ratings table and supported by thermal resistance data (θJA = 180°C/W for TSSOP-16). All electrical specifications-including resistance tolerance, tempco, and I²C timing-are ensured across this range, making AD5242BRU100 suitable for industrial and automotive under-hood applications where ambient temperatures exceed standard commercial limits.

Does the AD5242BRU100 retain its wiper setting after power cycling?

No, the AD5242BRU100 does not have nonvolatile memory and resets to midscale (code 0x80) on each power-up. This behavior is defined by its internal power-on preset circuit and is confirmed in the General Description and Theory of Operation sections. To maintain a specific setting across power cycles, the host microcontroller must reprogram the AD5242BRU100 via I²C during system initialization. The RDAC latch contents are preserved only during shutdown (SHDN asserted), not across power loss.

Can the AD5242BRU100 be used with a 3.3 V microcontroller I²C bus?

Yes, the AD5242BRU100 supports 3.3 V I²C operation. Its SDA and SCL inputs accept VIH ≥ 0.7 × VDD (so ≥2.31 V at VDD = 3.3 V) and VIL ≤ 0.3 × VDD (≤0.99 V), satisfying standard I²C level requirements. Pull-up resistors should be connected to the same 3.3 V supply as the microcontroller. The device's input leakage current (<1 µA) and capacitance (3 pF) ensure robust noise immunity and timing compliance at 400 kHz even with typical PCB trace lengths.

How does the AD5242BRU100 handle dual-supply operation?

The AD5242BRU100 supports true dual-supply operation with VDD = +2.7 V and VSS = −2.7 V, enabling bipolar signal handling in potentiometer divider mode. Terminal voltages VA, VB, and VW may swing between VSS and VDD, allowing AC-coupled signals (e.g., ±2 V audio) to be attenuated without clipping. However, the digital interface (SCL/SDA/AD0/AD1/SHDN) remains referenced to DGND and powered only by VDD-VSS is used exclusively for analog terminal biasing, not logic.

What is the purpose of the O1 and O2 pins on the AD5242BRU100?

O1 and O2 are programmable push-pull logic outputs controlled via bits in the I²C instruction byte. Each can source ≥40 µA at VOH ≥4 V or sink ≥1.6 mA at VOL ≤0.4 V when VDD = 5 V, enabling direct drive of LEDs, analog switches, or logic gates. They default to logic low at power-on and retain their last programmed state through shutdown. Unlike general-purpose GPIO, O1/O2 are tightly synchronized with RDAC updates-allowing coordinated analog/digital control in a single I²C transaction.