MP4571 SYNCO useage

The MP4571 has a CCM/SYNCO pin that can provide an out of phase clock. I have two MP4571s in my design, one providing a 24V rail, and one providing a 5V rail. I’d like to run them both on the same clock out of phase, but I don’t see much info on how to do that or if it is possible. Can you run one MP4571 off of another MP4571’s clock? If so, how?

Hi carpenter,

Thanks for your question.
Unfortunately, it is not possible to run one MP4571 off another MP4571’s clock. The oscillating frequency is set by an external resistor between the FREQ pin and GND. Refer to page 22 and Equation (1) on the datasheet.


I see, so when the datasheet says “This function allows two devices to operate in the same frequency, but 180° out of phase, which reduces the total input current ripple.” It’s referring to some other “not MP4571” device?

Yes exactly.
You will see some parts have a SYNC pin where you can feed the SYNCO clock from this part.