The MCP4018T-502E/LT is a 7-bit Single I2C? Digital Potentiometer with volatile memory. It features zero scale to full scale wiper operation, 7-bit resistor network resolution and simple I2C protocol with read & write commands. It is intended to be used in applications where a programmable resistance with moderate bandwidth is desired. The potentiometer's terminal B is the fixed connection to the zero scale (0x00 tap) wiper value of the digital potentiometer. The potentiometer's terminal A is the fixed connection to the full scale (0x7F tap) wiper value of the digital potentiometer. The VDD pin is the device's positive power supply input. The input power supply is relative to VSS and can range from 1.8 to 5.5V. A de-coupling capacitor on VDD (to VSS) is recommended to achieve maximum performance. The SCL pin is the serial clock pin of the I2C interface. The MCP401X acts only as a slave and the SCL pin accepts only external serial clocks. The SCL pin is an open-drain output.