We have custom board, having STM32F401VDT6 microcontroller on it. We interfaced a tricolor LED to the Timer 1 PWM channels (CH1- Red, CH2-Green, CH3-Blue). Recently we have ESD test, after that when we stop channel 2 PWM and started CH3 PWM that time CH2's pin is continuously high. But when CH2 PWM is started then this pin behaves as expected (High-Low).
> CH2's pin is continuously high
> when we stop channel 2 PWM and started CH3 PWM that time CH2's pin is continuously high
What is "stop channel 2 PWM" in terms of TIM (and perhaps GPIO) registers? Why is this behaviour unexpected?
If "stop channel 2 PWM" means effectively threestating the pin, ESD testing might've opened some leak path to VDD, e.g. shorted the transistor which switches on the internal pullup. There's probably also a higher current consumption when the pin is driven (PWM is on), but the difference may be low, depending on circumstances.