coupled inductor in the output filter
Posted by: andmaster
on
Hi guys!
Why do some circuits used coupled instead ordinary inductive OUTPUT filter (or common-mode). For example in topswitch-GX datasheet ,page 21, fig 42, L1 200 µH. What reasons?
Comments
Coupled Inductors help in cross-regulation in multiple output rails.
Hi Kanwar,
I agree on that. Thanks.
Regards,
PI-Picard
Hi Andmaster,
Thank you for your inquiry. The coupled common mode inductor at the output serves two purposes. One is for the EMI and the other one is to lower the output ripple. However, there will be likely more current ripple taken by the 1st capacitor of the filter circuit.
Regards,
PI-Picard