Hi,
We have been working on a new project using the TPS23753 for a POE product. Built a prototype, and built just the power supply. That works, nice and clean and stable. Now we have the first couple of boards with all the circuitry built, and we are having instability. High pitched whistling from the inductor. Tried adding a resistor load, makes little difference. Removed a large cap from the output, which got rid of the whistle, but the ripple is still big compared to the well behaved 1st proto with only the supply built.
I've laid out a number of switchers, and up until now, had good luck having them work. They were the much simpler non isolated ones though.
