Hello,
I originally tagged onto this thread: https://community.st.com/t5/stm32-mcus-products/stm32f103-hse-crystal-capacitors/td-p/771200 but I was recommended to make a separate thread.
Many of the STM32 datasheets, such as the STM32H753, say that the pin capacitance is 5pF per pin. When trying to size a crystal for the HSE oscillator, the designer is told to follow AN2867. When trying to calculate the stray capacitance we (at a minimum) add the pin capacitance of the two oscillator pins to get 10pF. The STM32H753 datasheet even says to approximate 10pF here on page 232:
AN2867 does not recommend any crystals for the STM32 HSE oscillator, so the assumption is that crystal has to have higher than 10pF load capacitance for STM32 devices.
I understand that pin capacitance would vary per package. Does ST have a more accurate estimation of pin capacitance? Or does ST have recommendations for crystals for the STM32 HSE oscillator?
Thanks,
Nino
