Microchip Technology MCP41100-I/SN

Overview

MCP41100-I/SN from Microchip Technology is a single-channel, 100 kΩ, 256-tap digital potentiometer in SOIC-8 package, featuring SPI™ interface (mode 0,0), ±1 LSB max INL/DNL, 1 µA static supply current, and operation from 2.7V to 5.5V across -40°C to +85°C industrial temperature range. It replaces mechanical potentiometers in precision gain/offset trimming of op-amp circuits.

For engineers reviewing the MCP41100-I/SN datasheet, MCP41100-I/SN pinout, MCP41100-I/SN application, or MCP41100-I/SN equivalent, key selection criteria include its 100 kΩ nominal resistance, 8-bit resolution, software shutdown capability, wiper resistance of 125–250 Ω (dependent on VDD), and compatibility with standard SPI controllers without external level-shifting.

Technical Context

The MCP41100-I/SN implements a linear resistor array with digitally controlled wiper position via an 8-bit register loaded through a synchronous SPI interface operating in mode 0,0 (CPOL = 0, CPHA = 0). Its internal architecture isolates digital control logic from analog terminals (PA0, PB0, PW0), enabling stable rheostat or voltage-divider configurations.

It supports software-initiated shutdown-disconnecting terminal A and shorting wiper to B-while retaining wiper register contents for immediate resumption. Power-up resets wiper to mid-scale (0x80), and no hardware reset or shutdown pins are present, distinguishing it from dual-channel MCP42XXX variants.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (SOIC-8, 150 mil width), RoHS-compliant, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5171BRMZ-100 and MCP42100-I/P, the MCP41100-I/SN offers optimal trade-off of SPI compatibility, 8-bit precision, and SOIC-8 footprint for single-pot applications where I²C is unavailable or dual channels are unnecessary.

Availability

MCP41100-I/SN is available at Aetrix Electronics and suitable for precision analog trimming, sensor signal conditioning, and programmable gain amplifier designs requiring stable component supply across industrial and automotive temperature ranges.

Supply support for MCP41100-I/SN 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

Microchip Technology Inc. is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, serving industrial, automotive, communications, and consumer markets.

The MCP41XXX family was designed specifically for replacing mechanical potentiometers in digitally controlled analog circuits, emphasizing SPI simplicity, low power, and guaranteed monotonicity across temperature.

FAQ

What is the maximum clock frequency supported by the MCP41100-I/SN SPI interface?

The MCP41100-I/SN supports up to 10 MHz SPI clock frequency at VDD = 5V. Timing parameters including tSU (40 ns setup), tHD (10 ns hold), and tDO (80 ns SO propagation delay) are specified across the full -40°C to +85°C range. Operation above 10 MHz is not guaranteed and may result in command corruption or register miswrites in the MCP41100-I/SN.

Does the MCP41100-I/SN have hardware reset or shutdown pins?

No, the MCP41100-I/SN does not include hardware reset (RS) or shutdown (SHDN) pins. These features are exclusive to the dual-channel MCP42XXX series (e.g., MCP42100). The MCP41100-I/SN supports only software-initiated shutdown via SPI command, which opens PA0 and connects PW0 to PB0 while preserving the wiper register value.

What is the wiper resistance specification for the MCP41100-I/SN at 3.3V supply?

At VDD = 3.3V and IW = 1 mA, the MCP41100-I/SN wiper resistance is specified as 175–250 Ω (max). This value is derived from the 50 kΩ/100 kΩ version DC characteristics table (DS11195C-page 3–4), confirmed for the 100 kΩ variant under 2.7V–3.3V conditions. It directly impacts insertion loss in rheostat-mode current sources.

Can the MCP41100-I/SN be used in rheostat mode with terminal A disconnected?

Yes, the MCP41100-I/SN supports rheostat mode by connecting either PA0 or PB0 to the circuit and leaving the other endpoint unconnected - but best practice per Microchip's Figure 4-1 and Section 4.1.1 is to tie the unused terminal to the wiper (PW0) to minimize parasitic capacitance and ensure predictable behavior. In shutdown mode, PA0 is opened and PW0 is internally shorted to PB0.

Is the MCP41100-I/SN pin-compatible with other MCP41XXX variants like MCP41010 or MCP41050?

Yes, all MCP41XXX devices (including MCP41010, MCP41050, and MCP41100) share identical SOIC-8 pinout and SPI command structure. Only the nominal resistance differs (10 kΩ, 50 kΩ, 100 kΩ); electrical parameters such as wiper resistance, tempco, and bandwidth scale accordingly. PCBs designed for one MCP41XXX can accept any variant without layout change.