AnsweredAssumed Answered

STM32F1xx and STM32F2xx HSI stability

Question asked by ELIK on Mar 13, 2012
Latest reply on Aug 5, 2012 by ELIK
Hello! I have a question to STM32xx chip manufacturers.
Last yar I uses STM32F10xx chips in my applications. It's 8mHz HSI works perfect - stable, with small temperature sensistivity - works very well.  CAN bus (slow) works perfect on these chips without crystals!

Now I decide to change chips to modern 32F2xxx, but after testing I see it's HSI works pure - very temperature/voltage sensitive, and somthing else...
In my application:
VCAP1 = 2.2uF
VCAP2 = 2.2uF
VDD1...5, VREF+ connects to 3.3v with 100uF capacitor
I have written the chip temp. monitoring loop in my application programm, but it helps to stabilize HSI frequency only for 60% chips (by manufacturer tape pack). 40% chips can't work anywhere..

Can someone say any way to make HSI stable same as STM32F10xx serie?