Abstract

This application note explains how to use the TPS65992S USB Type-C®/PD controller I2C controller feature to control two key companion devices in a USB-C Power Delivery system: the TPS55288 buck-boost regulator and the TUSB1044 linear redriver (USB Type-C crosspoint switch). This app note describes the necessary TPS65992S configuration for automated I2C control, the register settings for TPS55288 to manage VBUS voltages, and the settings for TUSB1044 to handle USB3/DisplayPort lane switching. Special attention is given to multi-byte I2C transactions (for example, setting the TPS55288 output voltage reference), the interpretation of TUSB1044 control register bits (CTLSEL, FLIP_SEL, EQ_OVERRIDE, and so on), and maintaining proper device behavior during attach, detach, and DisplayPort Alternate Mode events. Data sheet-backed explanations of each register value are provided to clarify the logic behind the configurations. The result is a coordinated design where the PD controller orchestrates power and data path changes seamlessly without needing an external microcontroller.