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STM32F439 power down GPIO state

PV C
Associate II

When STM32F439 power supply is dropping from 3.3V to 0V what will be state of GPIO which is configured as Mode output pp, pull up and speed_fast whether it will hold to value mentioned in GPIOx_ODR

1 REPLY 1
TDK
Guru

As the supply drops to 0V, at some point it crosses the BOR level (around 1.8V but it varies) at which the chip will enter a reset state and the GPIO pin will be set to default (typically input, no pull).

The chip can't output a high level on a pin with no power.

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