What are the differences between the PWM & PFM & auto skip mode on FS5600 PMIC？

[shafers]

What are the differences between the PWM & PFM & autoskip mode(SW mode) on FS5600 PMIC？

which one is more friendly for EMC performance？

Thanks

BR

Shafers

[JozefKozon]

Hi Louis,

the PWM keeps the same frequency of the waveform and changes the duty cycle, to change the power transferred, while the PFM modulation keeps the same duty cycle and changes the frequency to change the transferred power. 

JozefKozon_0-1692184721946.png

JozefKozon_1-1692184924554.png

In skip mode some of the pulses are skipped to lower the power transferred. 

JozefKozon_3-1692185147338.png

Regarding the EMC, the skip mode is the worse for the EMC to other devices. For the PWM and PFM, its not that easy to answer. It depends on many aspects. Please check a quote below.

JozefKozon_2-1692185114309.png

With Best Regards,

Jozef