UCC28951: Is it possible to design Constant Current using UCC28951?

Suttichai Chindaprayoonwong

Prodigy 50 points

Part Number: UCC28951
Other Parts Discussed in Thread: PMP9622

Hi TI team,

We need Constant current output 200V 6A, please advise if UCC28951 can do.

Now when output load draws high current over limit, with soft start enable SS/EN, UCC28951 will OFF then ON.

But what we want is UCC28951 to reduce output voltage and remain 6A CC output.

Thanks,

Suttichai

over 5 years ago

0 Benjamin Lough over 5 years ago

TI__Mastermind 26695 points

Hi Suttichai,

It is possible to design a PSFB with a constant current output where the output voltage reduces at heavy load. This can be done using CC-CV control using two feedback loops; one two regulate the maximum output voltage and the other to regulate the maximum output current. The two control loops are OR'd together. The control loop with the lowest error "wins" and controls the output. Here is a video that touches on this topic:https://training.ti.com/psfb-vs-fb-llc-part-1?cu=1135931.The CCCV discussion starts at 12:53. There is also a reference design example showing how to implement this. Take a look at PMP9622:http://www.ti.com/tool/PMP9622?keyMatch=phase%20shifted%20full%20bridge&tisearch=Search-EN-Everything.

Best Regards,

Ben Lough

Power management

Power management forum

UCC28951: Is it possible to design Constant Current using UCC28951?