Hi All
My customer is having an issue with a glitch in the dead time, see comments below
I’m running UCC28950 in some multi kilowatt full bridges here, and am experiencing a glitch and can’t tease out a solution:
We are having an issue with irregularity in the deadtime of the C/D half bridge. Note that this glitch does NOT appear in the A/B timing.
Basically, we are running with Fixed Delays on the Full bridge, by shorting the ADEL pin to Common. The basic delay is set with a resistor (33k) in the usual way. However, during operation, we occasionally experience a deadtime between C and D gate drive pulses that is much longer than expected. This glitch only occurs at loads above a certain threshold. The glitch is not synchronous with anything on the board, nor does it repeat at a fixed frequency.
This leads me to believe there is a noise issue or ground bounce – But I have to say that analog signals on this board are pretty well isolated from power currents. Any insights you could offer would be welcome.
UCD28950 dead time glitch.pptx
