2019-05-21 04:08 PM
I see that if using an external CMOS oscillator on just the OSC-IN pin that 0.3*VDD and 0.7VDD input levels or better are required. My external crystal oscillator using OSC-IN and OSC-OUT has a smaller voltage swing than 0.3VDD to 0.7VDD. Do the same levels apply in both cases? ST app note for oscillator design provides many other guidelines but not voltage levels.
2019-05-21 05:42 PM
usually its a small sine wave
this one H743,
is 0.3V peak to peak centered at 1.6V
8.0003MHz