2021-02-06 09:03 AM
Hello everyone,
I have an STM32F765VI MCU. When I work with internal clock it works fine. But when I switch to an external TCXO, It does not work properly. The TCXO output is a 26MHz sine wave with 1.5V peak to peak.
Does anyone know what may cause this problem?
What is the minimum amplitude of external clock which MCU can detect?
Thanks
2021-02-06 01:01 PM
Should be in the Data Sheet - "High-speed external user clock characteristics"
VIL is 0 to 1 V
VIH is 2.3 to 3.3 V
Expect you'd need to buffer or center the sine for it to work. Could try the non-bypass mode