Hi,
I'm testing a board with a couple of switchers on it (the only thing that is currently populated). The -8V inverting switcher is making a squealing nose. I have tracked it down to what looks like abnormal behaviour on the SW node of the switcher. The design and values were generated by webanch. I have attacked the schematic and 2 oscilographs of the SW node.
What I believe is causing the squealing is the 2kHz toggling of the "normal looking" square wave. Is this waveform normal for the SW node? If not what could be the problem.
Best regards,
Marko Antesic