Similar experience to
In my case, the behavior before initialization is typically as expected - PWM output of 0 per POR settings. In the problem cases, the PWM output appears to be a random digital output with a switching rate at a minimum of ~100ms as seen below.
This will continue until TruTherm is disabled (MMBT3904 used). The average on-time here is inversely related to the temperature at the sense diode.
I fully understand that initialization is required for the part, but I also expect the POR values to hold true until the initialization can be executed. Several devices have shown this undefined PWM output. I would like to understand if it is expected behavior for all devices or just a silicon variation that manifest in some percentage of parts or lot numbers.
