TPS65217: I want to turn off the power using the hardware reset function

Hanjun Kim,

The definition of the TPS65217 PB_IN pin is that if you hold the push-button down for >8s it will go through a Reset. In other words, it has the same functionality as if you were to press the RESETz button a single time.

I am not sure what the AM3358 processor is doing in the code when you press the push-button, but the PMIC definition clearly says PB_IN pressed > 8s = Reset system (power-down followed immediately by power-up) in Figure 24. Global State Diagram on page 39 of the datasheet.

If you want to sequence-down the PMIC without turning the rails back on, you would need to toggle the PWR_EN pin (PMIC_PWR_EN signal) low or set the SEQDWN bit to 1b. Both of these actions would be initiated by the processor's Linux software.

Since the PMIC is behaving as expected, you might want to start a new thread and ask the question about AM3358 instead of the TPS65217 PMIC.

The way to force the PMIC to shutdown (regardless of the processor) is to pull the PWR_EN pin low.

The processor controls the PMIC_PWR_EN pin, which is a push-pull output, but once the PWR_EN pin is forced low then the processor should pull PMIC_PWR_EN low due to PGOOD signal going low.

On the BOOSTXL-TPS652170, we use a physical ON/OFF switch to control the PWR_EN pin. We also use a physical switch to control a load switch that cuts off 5V power in front of the PMIC. Both of these options would shut-down your system.

If you prefer a push-button, you would want to implement a push-button circuit that behaves like a switch, which is why this App Note was written for PMICs:

Push-Button Circuit [for PMICs]