UCC28951-Q1: Is it suitable for the full bridge secondary?

VICKY SIRASWAR

Part Number: UCC28951-Q1
Other Parts Discussed in Thread: UCC2895, UCC28951

Hi, I plan to design a 3.3kW charger with an output voltage range of 54 to 90V and an input voltage range of 380 to 420. As the maximum output current is 40A and if I use a centre-tapped secondary in the PSFB stage, the voltage stress across the MOSFET is high and so is the cost. Can I use full-bridge config at the secondary side of PSFB and if so can you provide any reference for the same?

over 3 years ago

0 Mike O' over 3 years ago

TI__Guru* 86286 points

Hello,

I am looking into your inquiry and will get back to you shortly.

Regards,

0 Mike O' over 3 years ago in reply to Mike O'

TI__Guru* 86286 points

Hello,

I believe that you can use a full bridge on the secondary side. However, I do not have a reference design using one.

You might want to use the UCC2895 instead since it does not have SR drivers. I believe control the secondary full bride with the A and B drivers.

Regards,

0 VICKY SIRASWAR over 2 years ago in reply to Mike O'

Prodigy 100 points

Thanks for the reply. I wanted to know your expert opinion on an output voltage level of 54 to 90 and a maximum output current of 40A, which configuration on secondary will be efficient and suitable for this application?

0 Mike O' over 2 years ago in reply to VICKY SIRASWAR

TI__Guru* 86286 points

Hello,

I am looking into your inquiry and will get back to you shortly.

Regards,

0 VICKY SIRASWAR over 2 years ago in reply to Mike O'

Prodigy 100 points

Thanks Mike, please look into it.

0 Mike O' over 2 years ago in reply to VICKY SIRASWAR

TI__Guru* 86286 points

Hello Vickey,

Setting the output to 90 V will have lower RMS secondary currents compared to a 54 V output. This can reduce your I^2*R losses on the secondary.

This will have higher switching losses on the secondary compared to 54 V output.

If you set the output to 54 V it will have higher secondary RMS currents compare to a 54 V output. This will have higher I^2*R losses on the secondary.

This will have lower switching losses compared to the 90 V output.

What you need to do is evaluate both design possibilities and see what the effect on efficiency would be. I would go with the most efficient solution.

Regards,

Mike

0 VICKY SIRASWAR over 2 years ago in reply to Mike O'

Prodigy 100 points

Can I use UCC28951 for secondary full bridge rectification?

0 Mike O' over 2 years ago in reply to VICKY SIRASWAR

TI__Guru* 86286 points

Hello,

I believe you can use the UCC28951 with a secondary full bridge. However, the UCC2895 might be a better choice. This was discussed earlier in this thread.

Regards,

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UCC28951-Q1: Is it suitable for the full bridge secondary?