STM32L433 NRST pin status

[YISHIHARA]

This is a very basic question.
I built a custom board using the STM32L433.
After applying power (+3.3V), I checked the NRST pin state, but it did not reach the default voltage.
Could you please tell me any possible causes?
For reference, I have confirmed the STM32L433's power pin is at +3.3V. I have also confirmed the clock oscillator is operating at 4MHz.

Thank you in advance.

[Andrew Neil]

welcome to the forum.

Please see How to write your question to maximize your chances to find a solution for best results.

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@YISHIHARA wrote:

I built a custom board using the STM32L433..

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Please show the schematic, your PCB layout, and some good, clear photos.

See also: Application note AN4555, Getting started with STM32L4 Series and STM32L4+ Series hardware development

[TDK]

> I built a custom board using the STM32L433.

Which one? There are more letters/numbers after this.

If NRST is held low, it generally means the chip is not happy with the power supply. Perhaps you haven't connected ALL VDD pins to power, or not all VSS pins to ground, or part is not oriented correctly, or there are bad connections.