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why external crystal oscillator not working in STM32H7?

VPras
Associate II

Hi,

I am using STM32H7 Nucleo board. I soldered an external 25MHz crystal oscillator with 22 pf capacitors(Load capacitance of crystal =20pf) but the controller doesn't seem to work on 25Mhz crystal oscillator. I tested this by blinking an LED at 1 seconds but it is taking much longer time than usual. Also i tried replacing the crystal. although the internal oscillator HSI works fine. what could be the issue ?

Thanks

Vimal

7 REPLIES 7

Isn't there a solder bridge from the STLink's MCO, which has to be disconnected?

Refer to the Nucleo schematics/manual.

JW

Thank you. Issue is solved

Can you please tell us what was the problem?

JW

STLink's MCO has not been disconnected, that is why we were getting 8Mhz clock frequency everytime.

Hey can you tell me which 25Mhz crystal are you using i have been developing stm32f767 board and i require that crystal part number thank you

The STM32F7x9I-EVAL uses this NX3225HA 25MHz EXS00A-CH00343 (probably 12pF)

0693W000005D0W3QAK.jpg

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STM32H743I-EVAL

0693W000005D0XVQA0.jpg

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Up vote any posts that you find helpful, it shows what's working..