UCC28950 - H Bridge function

PaulSchoenke

Other Parts Discussed in Thread: UCC25600

Hello:

We are trying to use the TI: UCC28950PWR chip for controlling our H-bridge. However, we are not seeing the signals function as described for an H-bridge design. The chip says on page 14 that the minimum value is 13K for the delays and we had to set these well below 13K to get the signals to look appropriate.

Any guidance or input on this is welcomed and appreciated!

Thanks again!

Paul

over 13 years ago

0 Matt Bremmer over 13 years ago

Prodigy 35 points

Here is the H-bridge configuration. The UCC controller is connected to the fets with UCC27201D drivers.

We have to accept 18-32VDC in and convert this to 180-200VDC OUT.

The converter is required to be rated for a 200WATT output. We are not seeing the overlap of the mosfets which cancels the core of the transformer unless we turn the delays below 13K.

0 Matt Bremmer over 13 years ago

Prodigy 35 points

Here is the UCC controller configuration

0 CWilson over 13 years ago in reply to Matt Bremmer

Expert 1920 points

Why use that IC/topology for only 200W?

0 Matt Bremmer over 13 years ago in reply to CWilson

Prodigy 35 points

This is the topology that was recommended by an "expert" power supply designer that we had sub-contracted originally. One of the main reasons that we were trying to use this topology is the promises of 90%+ efficiencies.

What would you recommend?

0 CWilson over 12 years ago in reply to Matt Bremmer

Expert 1920 points

I'd use the UCC25600 and make a LLC Resonant Converter. I achieved +97% efficiency at 500W.

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UCC28950 - H Bridge function