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Associate II
Mar 17, 2025 9:51 PM UTC
Solved

STM32H755 HTRIM PIN high after POR

I'm working with a boost converter and have noticed that when resetting the device a PWM pin remains high/floating for a 100-200ms

I use the HRTIM with complementary inputs and deadtime insertion.
If my lowside pin remains floating/high for an extended period after reset it causes a dead short and will blow up stuff.
How do I set it up that on any reset or power loss the HRTIM PWM pins go low.

Am I supposed to use the fault behaviour?

Any help would be appreciated, thanks.

This topic has been closed for replies.
TDK
TDKBest answer
Mar 17, 2025 10:16 PM UTC

After reset, almost all pins are in a high impedance state. There is no way to change this behavior.

If you need them to be high or low during and directly after reset, an external pullup or pulldown resistor on the board is needed.

"If you feel a post has answered your question, please click ""Accept as Solution""."

1 reply

TDK
TDKBest answer
Mar 17, 2025 10:16 PM UTC

After reset, almost all pins are in a high impedance state. There is no way to change this behavior.

If you need them to be high or low during and directly after reset, an external pullup or pulldown resistor on the board is needed.

"If you feel a post has answered your question, please click ""Accept as Solution""."