Looking at the discussion here (
https://electronics.stackexchange.com/questions/398132/usb-power-cleaning/398152) on USB power filtering I see the interesting AP1158ADS capacitance multiplier part. I've got a design using USB power to a +/- 5VDC DC-DC converter that then goes to some +/-3.3 VDC linear regulators to help get the cleanest possible analog rails. This is already a rather high BOM line item board, so this filter module looks great! Does anyone know of a similar P/N for cleaning up the negative rail? I've looked to no avail and really don't want to implement it from scratch if possible. Putting this before the DC-DC converter would seem pointless, yes?