Analog Devices Inc./Maxim Integrated DS1867S-50

Overview

DS1867S-50 from Maxim Integrated (now Analog Devices) is a dual nonvolatile digital potentiometer with EEPROM, providing two independent 256-position, 50 kΩ end-to-end resistors for precision analog trimming in power management and sensor calibration circuits. It operates from a single 5V supply, retains wiper settings without power, and communicates via a 3-wire serial interface.

For engineers reviewing the DS1867S-50 datasheet, DS1867S-50 pinout, DS1867S-50 application, or DS1867S-50 equivalent, key selection considerations include its 50 kΩ resistance value, ±0.75 LSB absolute linearity, industrial temperature range (–40°C to +85°C), EEPROM endurance (>25,000 writes), and SOIC-16 surface-mount package compatibility.

Technical Context

The DS1867S-50 implements two independent 8-bit digitally controlled resistive dividers, each with wiper positions stored in on-chip EEPROM shadow memory. Its 3-wire serial port (RST, CLK, DQ) enables write-and-read access to both wiper registers and a stack-select bit, supporting cascaded multi-device control over a shared bus.

It supports stacked configuration (series connection of both pots) yielding 512 effective steps and selectable SOUT output from either W0 or W1 based on the stack-select bit. Nonvolatility is triggered automatically during power-down when VCC drops below 4.5 V, requiring ≥4 ms to complete EEPROM storage with guaranteed retention.

Key Specifications

Pinout & Package

DS1867S-50 is packaged in a 16-pin SOIC (300-mil) surface-mount outline with exposed pad not present; pin assignments are fully defined per Maxim's mechanical drawings and match the DS1867 family SOIC variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5232BRUZ10 and MCP42050-I/P, DS1867S-50 uniquely combines 50 kΩ resistance, 3-wire simplicity, and guaranteed nonvolatility-making it optimal for retrofitting legacy 5V systems needing zero-failure calibration retention without firmware redesign.

Availability

DS1867S-50 is available at Aetrix Electronics and suitable for motor control feedback calibration, inverting variable-gain amplifiers, fixed-gain signal attenuators, power supply trim & margining, and industrial sensor signal conditioning requiring stable component supply and long-term calibration integrity.

Supply support for DS1867S-50 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 (via acquisition of Maxim Integrated) designs high-performance analog, mixed-signal, and RF ICs for precision measurement, power, and connectivity applications.

The DS1867S-50 belongs to Maxim's digital potentiometer product line, engineered specifically for replacing mechanical trimpots in industrial and instrumentation systems where calibration stability and EEPROM-based nonvolatility are mandatory.

FAQ

What is the maximum clock frequency supported by the DS1867S-50 serial interface?

The DS1867S-50 supports a maximum CLK frequency of 10 MHz, enabling rapid wiper updates in time-critical applications. This specification is verified across the full industrial temperature range (–40°C to +85°C) and ensures reliable data latching on the rising edge of CLK. The DS1867S-50 also specifies minimum pulse widths (tCH ≥ 50 ns) and setup/hold times to guarantee robust timing margins in noisy environments.

Does the DS1867S-50 retain wiper settings after power removal, and how is this achieved?

Yes, the DS1867S-50 retains wiper settings after power removal using on-chip EEPROM shadow memory. When VCC drops below 4.5 V, the DS1867S-50 initiates an automatic storage sequence that saves the current 17-bit I/O shift register contents-including both wiper positions and the stack-select bit-to nonvolatile memory, provided the power-down time exceeds 4 ms. This mechanism ensures DS1867S-50 maintains calibration without external components or host intervention.

Can the two potentiometers in the DS1867S-50 be used independently, or must they be stacked?

The two potentiometers in the DS1867S-50 operate fully independently-each with its own H, L, and W terminals-and do not require stacking. Stacking is an optional configuration enabled by connecting H1 to L0 and using SOUT as the combined output. The DS1867S-50's 3-wire interface allows individual read/write access to both wiper registers, making independent use the default and most common implementation for dual-channel trimming tasks.

What is the wiper resistance specification for the DS1867S-50, and how does it affect circuit design?

The DS1867S-50 has a wiper resistance of 400 Ω to 1000 Ω, varying with wiper voltage and position. This parameter directly impacts loading effects in high-impedance circuits: designers must ensure connected loads (e.g., op-amp inputs) present ≥10× higher impedance than the worst-case wiper resistance to avoid gain error. The DS1867S-50 datasheet recommends using high-Z buffers or selecting R1 ≫ RW in attenuator configurations to minimize this effect.

Is the DS1867S-50 pin-compatible with other variants in the DS1867 family, such as DS1867S-10 or DS1867S-100?

Yes, the DS1867S-50 is pin-compatible with DS1867S-10 and DS1867S-100-all share identical 16-pin SOIC packaging, pinout, electrical interface, and command protocol. The sole difference is end-to-end resistance value (10 kΩ, 50 kΩ, or 100 kΩ), which affects step resolution, thermal noise, and voltage handling. This interchangeability allows designers to select resistance value based on application requirements without modifying PCB layout or firmware.