cancel
Showing results for 
Search instead for 
Did you mean: 

MEMS oscillators not compatible with STM32F1 and STM32L1 series?

Andrew Neil
Evangelist III

Just came across this post:

https://community.st.com/t5/stm32-mcus-products/oscillator-selection-for-stm32g4/m-p/571716/highlight/true#M217792

which quotes AN2867 saying that MEMS oscillators are, "compatible with all STM32 MCUs/MPUs, except for the STM32F1 and STM32L1 series." 
(my emphasis)

 

AndrewNeil_1-1711360075906.png

 

So what is it that makes the F1 and L1 unable to use MEMS oscillators?

2 REPLIES 2
Bouraoui Chemli
ST Employee

 

This could be due to the maximum input rise and fall time. For the STM32F1, it is 50 ns as indicated in Table 21 of the datasheet. In a MEMS oscillator, it can reach up to 100 or 200 ns.

It would be good if AN2867 stated the reason(s) - rather than just dismissing the F1 and L1