2008-06-02 08:01 AM
Using USB with internal Oscillator possible?
2011-05-17 03:35 AM
Hello,
we develop a very small and cost sensitive circuitry that is a USB device. Looking for affordable and small resonators/crystals we considered to use the internal oscillator of the STM32F203T8 instead. Is this possible and reliable enough?2011-05-17 03:35 AM
USB full speed requires crystal. (I think the stm32 can't do low speed.)
maybe you could run at 48MHz from HSI+PLL, while continually calibrating in software from LSE running a 32KHz crystal (these are cheaper, aren't they?), but you may have too much jitter.2011-05-17 03:35 AM
Years past we had similar issue while attaching 2 micros
via Uart. Equation uncovered acceptable variance between the ''fastest'' sender versus the ''slowest'' receiver. However - the issues of temperature and aging also arose. Crystal & resonator solved this in the past - I especially like lanchon's 32Khz xtal ''reference'' suggestion. It's unfortunate that ''normal'' xtals for STM32 are BIGGER than the micro...