Tool/software:
I'm facing an issue where the BQ76972 fails to communicate with an STM32 microcontroller over I²C at 400 kHz, but it works fine at 100 kHz. I measured the rise time to be around 1250 ns, which does exceed the BQ76972's datasheet maximum. So, I tried lowering the pull-up resistor from 10 kΩ to 4.7 kΩ, 2.2 kΩ, and 1.5 kΩ, but that didn’t resolve the issue.
Interestingly, communication only works at 400 kHz when I connect an oscilloscope probe or logic analyzer to the bus. Could this be a signal integrity or capacitance issue? Any suggestions on what's causing this behavior and how to fix it?