Hi Everyone,
I have recently been experimenting with the TPS563200 to convert 12V into 3.3V to power a 3g modem (which draws a max of 2.5A); however, whenever I connect the modem, the TPS563200 starts making a loud, high pitched ticking noise and immediately drops its output voltage to a few hundred millivolts (when probed with a multimeter). Even after the 3g modem is disconnected, the TPS563200 continues to make the noise and output a really low voltage. It seems as though attempting to power the modem from this buck converter just once, damages the buck converter and it can no longer be used. I probed the output of the TPS563200 (using a logic analyser with analogue inputs) after disconnecting the modem (therefore no load) and this what it looks like:
If I reconnect the 3g modem, this waveform is still the same.
So far this has happened to 4 of TPS563200's and I'm not sure what the cause of the problem is? The max current draw of the modem is 2.5A and the max output of this buck converter is 3A, I doubt it is an over-current issue. Using a heatgun on the TPS563200 indicates that it does not go over 35°C.
Here is my schematic:
Any insights would be greatly appreciated.
Cheers,
Jake
