Hi all,
we use the LM26001 for a 5 V supply. At low current we set FPWM mode on, the switcher works than in a discontinued mode.
Every 250us some on pulses are seen. This follow-up of the pulses results in a 4 khz ripple voltage an we can hear it because it is transferred by
a ceramic capacitor to the main board. Is there a chance to increase this repetition frequency in a area where it is not hearable?
It can be seen, that by using different electrolyt capacitors and ceramic capacitors with lower value that this repetition frequency increase,
but we didn't know exactly what's the reason.
regards
Michael