The device uses an I²C compatible interface for flexible charging parameter programming and instantaneous device status reporting. I²C^TM is a bi-directional 2-wire serial interface developed by Philips Semiconductor (now NXP Semiconductors). Only two bus lines are required: a serial data line (SDA) and a serial clock line (SCL). Devices can be considered as masters or slaves when performing data transfers. A master is the device which initiates a data transfer on the bus and generates the clock signals to permit that transfer. At that time, any device addressed is considered a slave.

The device operates as a slave device with address 6AH, receiving control inputs from the master device like a microcontroller or a digital signal processor through REG00 to REG0C. A register read beyond REG0C returns 0xFF. The I²C interface supports both standard mode (up to 100 kbits), and fast mode (up to 400 kbits), connecting to the positive supply voltage via a current source or pullup resistor. When the bus is free, both lines are HIGH. The SDA and SCL pins are open drain.