6 Replies Latest reply on May 22, 2014 8:40 PM by ki.leung

    Fine tune PWM frequency of 32768 Hz within +/-5Hz range




      I need to finely tune frequency of PWM output of PSoC 5LP within approx +/-10Hz, centered at 32.768 kHz (standard Quartz oscillator frequency). I need such fine-tuning to syncronize 32.76 kHz signals on two separate devices within approx. <0.5 Hz. (clock sharing between devices is NOT possible). I thought that all Quartz resonators are closely matched, but as I go through them, frequency deviation from one to another can be as much as 10 Hz. I can pre-select a pair of relatively closely matched Quartz resonators, but some fine adjustment of the frequency is still required.


      Is there any PLL possibilities of PSoC5LP for fine adjustment of the output frequency with resolution 0.1 Hz? What other possibilities exist to fine-tune Quartz frequency: adjusting Quartz oscillator driving voltage, changing bypassing capacitors, temperature?