5 Summary of I2C Event Table

By using the TPS65992 I2C controller feature, we achieved coordinated control of both the power supply (TPS55288) and the signal redriver (TUSB1044) in response to Type-C events. Table 5-1 below summarizes all the configured I2C events, including the index, trigger, target device register, and data written:

(Table entries reflect the configuration described above. “REG0x00” with two data bytes implies a multi-byte write starting at 0x00. Unused index 8 is left for future expansion or other events if needed. Orientation-independent writes (like to 0x0C, 0x10, 0x20) were duplicated under both UU and UD triggers in our table for completeness, although the data is identical.)

As shown, the TPS65992S handles a wide range of events – from initial power-up of the port, through cable attachment in either orientation, through USB PD contract negotiation, and into DisplayPort Alternate Mode – all by executing predefined I2C transactions. This event-driven control scheme maintains that at each stage, the external hardware (power converter and redriver) is in the proper state:

• At reset and detach, the power is safe (5V or off) and high-speed switches are reset.
• On attach, the power stays at 5V until higher voltage is requested, and the USB3 redriver connects the Superspeed lanes correctly.
• When a higher voltage PDO is requested, the PD controller raises the TPS55288’s output to the required level.
• If DisplayPort mode is entered, the PD controller reconfigures the redriver so that the correct lanes carry DisplayPort and any remaining lanes carry USB3, adjusting EQ settings as needed for signal integrity.
• All of this occurs autonomously, without real-time software intervention, once the PD controller is programmed through the customization tool.

Conclusion

Using the TPS65992S integrated I2C host capability, a USB-C PD system can tightly coordinate power delivery and high-speed signal switching. In this application, the TPS65992S configures the TPS55288 buck-boost converter to output the appropriate voltage for each PD contract and manages the TUSB1044 redriver to route USB3/DisplayPort signals correctly for any cable orientation and mode. The elimination of logical inconsistencies (such as verifying the converter is enabled only after setting the correct voltage, and the redriver is never in an undefined state during mode switches) is achieved through careful event ordering in the PD controller firmware.

This approach replaces what can otherwise require an external MCU or complex GPIO logic with a firmware-driven design that is easier to maintain and update using TI’s tool. Each critical event (attach, detach, contract negotiation, mode entry) triggers a predefined sequence, maintaining the hardware state always aligns with the USB-C state.

The result is a robust design where, for example, when a laptop is plugged into a monitor: the Type-C controller immediately configures the TUSB1044 for the correct orientation, then negotiates a higher voltage and signals the TPS55288 to ramp up to 20V for charging, and when DisplayPort Alt Mode is initiated, reconfigures the redriver so the display comes to life – all in a fraction of a second and without user intervention. This demonstrates the power of an integrated PD controller design.