Hello,
I am designing a synchronous buck converter using the LM5117, and I have a couple of questions about syncing this chip to an external clock.
- I am running at 230kHz, and I would like to dither this frequency within +/-10% to reduce EMI. To this end, I would like to use an external voltage-controlled oscillator at 230kHz with a dithered frequency, and feed it into the RT pin via a small capacitor, as the datasheet instructs. Would this work?
- My design utilizes two of these buck converters in parallel, each running off of the same 28VDC power supply. If possible, I would like to feed one of them with the external clock, while feeding the other one with the complement of the external clock. The idea is that the high-side FET on one of the bucks would be ON while the other one is OFF, so that neither are pulling current from the input at the same time. This would also be done to reduce EMI; by making the input current from the 28VDC more like a "DC" current.
I would like to hear your thoughts!
Thanks,
Dan
