UCC24612: UCC24612 used in phase-shifted full-bridge topologies, the drive is shut down early.

zhongsen

Part Number: UCC24612

The purple waveform in the figure refers to the drive waveform provided by the UCC24612, while the yellow waveform refers to the voltage across the DS of the phase-shifted full-bridge secondary side MOSFET. Is this phenomenon due to the fact that the current at the end of freewheeling is too small, so the drive is turned off . Or is it due to the logic inside UCC24612 that is not suitable for phase-shifted full-bridge topology?

over 1 year ago

0 Sean Xu over 1 year ago

TI__Genius 14580 points

UCC24612 control driver waveform to prevent negative current. If you don't want negative current, the UCC is good to use. Otherwise, it is not suitable to use this part in PSF B.

0 zhongsen over 1 year ago in reply to Sean Xu

Prodigy 20 points

May I ask if the negative current you mentioned refers to the current flowing from drain to the source? If so, I adopt a full-wave rectification method on the secondary side, and there should be no negative current. In the figure I provided, it can also be seen that the voltage between the DS of MOSFET is less than 0 for a long time, but the driver did not fully cover the negative pressure section. What is the reason for this?

0 Sean Xu over 1 year ago in reply to zhongsen

TI__Genius 14580 points

Yes, the negative current flows from Drain to source. In full bridge, it is ok to have negative current, which is different from flyback/forward topology. You can check output inductor current together to make sure the current flow correctly.

0 zhongsen over 1 year ago in reply to Sean Xu

Prodigy 20 points

Thank you for your reply,I will check the current.

0 Sean Xu over 1 year ago in reply to zhongsen

TI__Genius 14580 points

Good, thanks

Power management

Power management forum

UCC24612: UCC24612 used in phase-shifted full-bridge topologies, the drive is shut down early.