TPS25751: TPS25751 start up from NegotiateHighVoltage

Hi Gary,

Thanks for reaching out on E2E!

Gary Teng said:

1. If they want to start up TPS25751 from NegotiateHighVoltage, can they load code from EC after the Vin3V3 is ready and send GAID to TPS25751?

2. If they don't want to code reset PD in NegotiateHighVoltage startup, is there any method to set up PD? Write register directly or?

For negotiate high voltage, the PD will come up into APP mode even without VIN3V3 present. What we can do with an external EC is once VIN3V3 is present, they can issue the GAID command to reset the PD controller and put it back into PTCH mode. After that the system can then send the patch over I2C. Let me confirm with the team if there are any issues in supporting this and that there is no case where we cannot put the PD into patch mode.

Gary Teng said:

3. What's the main different between using 1 or 2 GPIO for liquid detect function?

For Liquid detection the only pin assignments that are required are ADC3 and ADC4, those GPIO definitions cannot change. The other GPIO events can be configured to any other GPIO, but both NMOS and PMOS GPIO controls are needed to control the liquid detection circuit.

Thank you,

Kevin

Hi Gary,

Of course!

There is no way to speed up the update process and do it in another way outside what is described in the I2C programming guide.

Gary Teng said:

About 1/2 GPIO controlled for liquid detection, my customer want to know the what's the advandate for using 1 or 2 GPIO to monitor external status. Would you please help to explane it? Thanks.

For monitoring the status of liquid detection, you can either use an I2C IRQ, or the GPIO event. My comment was in regards to the GPIO control of the NFET and PFET of the circuit.

Thank you,

Kevin