UCC14241-Q1: Common mode choke recommendation

Jitendra Jain

Part Number: UCC14241-Q1

Tool/software:

Dear TI expert,

We're designing SiC gate driver power supply with UCC14241. Common mode choke is typically required in the input of power supply.

- What is the recommendation for CMC with UCC14241

- Addition of CMC would affect digital pins, EN and PG, status because CMC would come between power supply ground and MCU ground. We want to use EN for optimizing standby consumption.

Regards,

Jitendra

4 months ago

0 Steven Mappus1 4 months ago

TI__Mastermind 27785 points

CMC configuration example:

Regards,

Steve

0 Jitendra Jain 4 months ago in reply to Steven Mappus1

Intellectual 255 points

Dear Steven,

Thanks for the suggestion.

In our case, MCU circuitry is powered from VIN+ and VIN-. So, we are still figuring out on how to connect EN, PG to MCU as GNDP and VIN- are not at same potential.

Regards,

Jitendra

0 Steven Mappus1 4 months ago in reply to Jitendra Jain

TI__Mastermind 27785 points

In this case you might consider translating EN and /PG signal through a digital isolator?

Steve

0 Jitendra Jain 3 months ago in reply to Steven Mappus1

Intellectual 255 points

Dear Steven,

Thanks for the suggestion. This should work.

But here we assume that noise couples only through power supply pins of UCC14241. Is there any reference which explain this well why there is no common mode noise in signal pins of UCC14241 or how digital isolator would not allow it.

Regards,

Jitendra

+1 Steven Mappus1 3 months ago in reply to Jitendra Jain

TI__Mastermind 27785 points

For the single UCC14241-Q1 CISPR 25 EMI compliance report, we only connect the EN and /PG local to the UCC14241-Q1. In an application where these signals are passed through a digital isolator, there could be some additional CM noise present but unclear how this might couple into the input voltage supply lines? If there is concern you could add another CMC (or ferrite beads or X2Y capacitors) in the EN, /PG signal lines. The current is much lower in this path compared to the VINP path.

Steve

0 Jitendra Jain 3 months ago in reply to Steven Mappus1

Intellectual 255 points

Thanks.

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

Power management

Power management forum

UCC14241-Q1: Common mode choke recommendation