MCP40D18T-503AE/LT

Overview

The MCP40D18T-503AE/LT is a single-channel digital potentiometer featuring a 7-bit resistor network with 128 adjustable taps. It utilizes an I²C serial control interface and volatile RAM memory to store wiper settings. The device supports both potentiometer and rheostat configurations, offering end-to-end resistance values of 5 kΩ, 10 kΩ, 50 kΩ, or 100 kΩ. Key electrical characteristics include a typical wiper resistance of 100 Ω, low temperature coefficients (50 ppm/°C absolute, 15 ppm/°C ratiometric), and operation across a supply voltage range of 1.8V to 5.5V. It operates within an extended temperature range of -40°C to +125°C.

Feature Summary

• I²C Serial Interface: Supports SMBus 2.0 Write Byte/Word and Read Byte/Word protocol formats for efficient communication.
• Configurable Resistance: Offers R_AB resistance options of 5 kΩ, 10 kΩ, 50 kΩ, or 100 kΩ with 128 discrete steps.
• Low Power Consumption: Features low static current consumption of 2.5 µA (typical) when the serial interface is inactive.
• Protection Features: Includes Brown-out Reset protection at 1.5V (typical) and power-on default wiper setting at mid-scale.

Applications

• PC Servers utilizing I²C protocol with command codes
• Amplifier gain control and offset adjustment circuits
• Sensor calibration for pressure, temperature, position, optical, and chemical sensors
• Set point or offset trimming in electronic systems
• RF amplifier biasing networks

Procurement Notes

Verify the specific ordering suffix 'AE' against official Microchip documentation to confirm package type and temperature grade specifications. Ensure the selected variant matches the required I²C address configuration, as the MCP40D18 family offers alternative addresses. Confirm that the volatile memory architecture aligns with system requirements for power-loss data retention.

Selection Notes

Select this component for applications requiring precise digital resistance adjustment via I²C without non-volatile storage needs. The 7-bit resolution provides 128 steps suitable for general-purpose trimming. Consider the 100 Ω typical wiper resistance when designing high-current paths. Verify compatibility with the host controller's I²C clock speed, supporting up to 400 kHz in Fast Mode.

Part Context

This part belongs to the MCP40D17/18/19 family of 7-bit digital potentiometers. The MCP40D18 specifically denotes the Potentiometer configuration variant housed in a SC70-6 package. It shares core features with the MCP40D17 (Rheostat, SC70-6) and MCP40D19 (Rheostat, SC70-5), differing primarily in terminal configuration and pinout.

Replacement Considerations

MCP4018T-503E/LT: Similar I²C digital potentiometer but uses a simplified command format for higher throughput. MCP40D17T-503E/LT: Identical package and interface but configured as a Rheostat rather than a Potentiometer.