AnsweredAssumed Answered

Minimizing clock drift on Kinetis microcontroller

Question asked by rampsr on Jun 8, 2015
Latest reply on Jun 11, 2015 by Norm Davies

I'm using the Kinetis MKL05Z microcontroller and trying to minimize the amount of clock drift from device to device. Here's the situation:

 

I've got a product that uses the Kinetis microcontroller (L Series) and when the product is turned on, four pins send out PWM signals and change their duty cycles in a repetitive pattern with the period of the pattern lasting several seconds. After several minutes, each device drifts out of sync from one another. Eventually the devices can become 180 degrees out of phase. These devices are independent of one another so there is currently no way to share common signal between them. Also, the PCB temperature around the microcontroller may see up to 90 degrees Celsius at times.So I notice the clock drift gets a lot worse at elevated temperatures (at least according to my oscilloscope).

 

So that's my situation without getting very detailed. Basically, I have timers running and want to know if there is a trick to always end up with a constant, dependable, and precise timer where each microcontroller (from device to device) ends up at the same counter value after minutes or even hours of running.

 

Someone mentioned Phased Locked Loop, or something like that, but I don't know much about that.

 

Thanks,

Outcomes