UCC28740: Brown in/Out protection

Mia Ma

Part Number: UCC28740
Other Parts Discussed in Thread: UCC28742, UCC28782

Tool/software:

Hi team,

For our UCC28740, we are positioning the brown in and brown-out point with the Vs current generated by Rs1 as below description.

Could you pls help to clarified that if there is a delay to restart after the brown-out fault is triggered? Or only as the brown-in point it triggered, the part is retrying immediately?

Thanks

Best regards

Mia

over 1 year ago

0 Manuel Alva Hernandez over 1 year ago

TI__Genius 15566 points

Hi Mia,

In order to trigger the brown out is (stop) and brown in (run), the VS voltage needs to reflect those voltages (Ivsl_run*Rsv2 and Ivsl_stop*Rsv1) during three cycle times. After that, the controller/device will immediately stop switching (brown out) or keep switching (brown in) to deliver power to the secondary side. This is not specified in the UCC28740 DS (not sure why), but it is specified in UCC28742 for example.

Thank you

0 Mia Ma over 1 year ago in reply to Manuel Alva Hernandez

TI__Intellectual 2515 points

Hi Manuel

Thanks for your feedback.

So if it's also the same rule as UCC28782, once stop switching, the part will discharge the VDD to Vddoff, and after that, the part do the restart process?

Thanks

Best regards

Mia

0 Manuel Alva Hernandez over 1 year ago in reply to Mia Ma

TI__Genius 15566 points

Mia,

That is correct.

Thank you

Power management

Power management forum

UCC28740: Brown in/Out protection