Analog Devices Inc. AD5271BRMZ-20

Overview

AD5271BRMZ-20 from Analog Devices is a single-channel, 256-position digital rheostat with 20 kΩ nominal resistance, ±1% end-to-end resistor tolerance error, SPI interface, and 50-times programmable (50-TP) nonvolatile wiper memory. It operates from 2.7 V to 5.5 V single supply or ±2.5 V dual supply and features 5 ppm/°C temperature coefficient in rheostat mode-used for precision gain control in industrial instrumentation amplifiers.

For engineers reviewing the AD5271BRMZ-20 datasheet, AD5271BRMZ-20 pinout, AD5271BRMZ-20 application, or AD5271BRMZ-20 equivalent, key selection considerations include guaranteed 1% resistor tolerance in R-Perf mode, 8-bit resolution, 300 kHz bandwidth at 20 kΩ, wiper readback capability, and compatibility with bipolar ac signal adjustment via dual-supply operation.

Technical Context

The AD5271BRMZ-20 implements a segmented resistor ladder architecture with digitally controlled CMOS switches, enabling precise rheostat-mode operation between terminals A and W. Its 50-TP memory uses permanent fuse-based storage-no external programming voltage required-and supports power-on auto-refresh of the last stored wiper position.

It employs a 16-bit SPI-compatible serial interface (SYNC, SCLK, DIN, SDO) with CPOL = 0, CPHA = 1 timing, supporting up to 50 MHz clock rates. The RDAC register acts as a volatile scratchpad; write commands (Command 1) update wiper position instantly, while Command 3 initiates irreversible 50-TP programming lasting ~350 ms.

Key Specifications

Pinout & Package

AD5271BRMZ-20 is housed in a compact 10-lead MSOP package (3 mm × 4.9 mm × 1.1 mm), optimized for space-constrained PCB layouts while maintaining thermal performance (θJA = 161.8°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5272BRMZ-20 and MCP41HV51-203, the AD5271BRMZ-20 uniquely delivers guaranteed ±1% end-to-end tolerance in R-Perf mode alongside true 50-TP nonvolatility-making it the only option qualified for unattended, maintenance-free calibration in safety-critical instrumentation.

Availability

AD5271BRMZ-20 is available at Aetrix Electronics and suitable for industrial instrumentation, programmable power supplies, sensor calibration systems, and precision filter design requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD5271BRMZ-20 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, serving precision measurement, industrial automation, and communications markets since 1965.

The AD5270/AD5271 family was designed specifically for high-accuracy, maintenance-free analog tuning-targeting applications where mechanical potentiometers fail due to wear, vibration, or environmental stress.

FAQ

What is the guaranteed resistor tolerance for AD5271BRMZ-20 in precision applications?

The AD5271BRMZ-20 guarantees ±1% end-to-end resistor tolerance error in R-Perf mode across −40°C to +125°C when operating within specified voltage ranges. This is achieved through on-chip calibration and applies to codes from 0x1E to 0xFF at |VDD−VSS| = 4.5 V to 5.5 V, enabling open-loop use without external trimming. The AD5271BRMZ-20 achieves this specification without requiring user calibration routines or factory programming.

Does AD5271BRMZ-20 support dual-supply operation for bipolar signal adjustment?

Yes, the AD5271BRMZ-20 supports ±2.5 V dual-supply operation, allowing Terminal A and W to swing symmetrically around ground. This enables true ground-referenced rheostat operation for ac-coupled signals-such as audio or sensor outputs-without level-shifting circuitry. The AD5271BRMZ-20 maintains full 256-position resolution and ±1% tolerance under dual-supply conditions, as verified in Table 4 of the Rev. H datasheet.

How many times can the 50-TP memory of AD5271BRMZ-20 be programmed?

The AD5271BRMZ-20 contains 50 independent fuse-based memory locations, allowing up to 50 permanent wiper position writes. Each program cycle consumes ~4 mA for 55 ms and completes in ~350 ms total. Once programmed, values persist indefinitely without power. The AD5271BRMZ-20 does not support erasure or reuse of programmed locations-each write advances to the next address until all 50 are exhausted.

Can AD5271BRMZ-20 wiper position be read back in real time?

Yes, the AD5271BRMZ-20 supports wiper position readback via SPI Command 2 (RDAC register read). This returns the current 8-bit wiper code on the SDO line, enabling closed-loop verification, fault detection, and dynamic recalibration. The AD5271BRMZ-20 executes this read in ≤6 µs, and the value reflects the actual analog wiper state-not just the last written register value-ensuring functional correctness.

What package type and footprint does AD5271BRMZ-20 use?

The AD5271BRMZ-20 uses a 10-lead MSOP package (3 mm × 4.9 mm × 1.1 mm) with standard JEDEC MO-187AC dimensions. It features exposed pad (EPAD) that may be left floating or tied to VSS for improved thermal performance. The AD5271BRMZ-20 pinout matches industry-standard MSOP-10 layouts, enabling drop-in replacement in existing designs using compatible footprints.