UCC28070: For the Interleaved PFC using UCC28070, can we place the CT in between the INDUCTOR and MOSFET-DIODE node?

Surya R

Part Number: UCC28070

Tool/software:

Hi,

As per the UCC28070 datasheet, it recommends connecting the CT in between the INDUCTOR-DIODE node and MOSFET. So that it will sense the Current only during the MOSFET ON.
But i understood that it will be the same if we place the CT in between the INDUCTOR and MOSFET-DIODE node.

Please provide the difference in operation and Key considerations.

Thank you.

Regards,
Surya

2 months ago

0 Ulrich Goerke 2 months ago

TI__Mastermind 40480 points

Hello Surya,

It is definitely NOT the same if the current-sense transformer (CT) is place in series with the inductor rather than in series with the MOSFET drain.

Please see my reply in this thread from yesterday:
UCC28070: Current transformer placement in series with inductor or MOSFET

I tried to reply to the thread yesterday, but our E2E system was having troubles and I was unable to post it then. Instead, I had a meeting with Julius who is supporting you and explained the situation. E2E is working properly again and I was able to post my reply just a few minutes ago.

Regards,
Ulrich

Power management

Power management forum

UCC28070: For the Interleaved PFC using UCC28070, can we place the CT in between the INDUCTOR and MOSFET-DIODE node?