UCC21750-Q1: desat

Yuhao Wang

Part Number: UCC21750-Q1

Hello,


I would like to ask, is it necessary to add D1 and D2 protection diodes to the external detection circuit of the DESAT pin of the UCC21750-Q1 chip? If necessary, can D1 be replaced with a voltage regulator tube? "Adjust resistor R1" or "add D4 voltage regulator tube" to adjust the desaturation trigger threshold, which one do you recommend more?

4 months ago

0 Sasikala Thangam 4 months ago

TI__Expert 5520 points

Hi Yuhao Wang,

Yes, Its recommended to plan Schottky diode for faster -ve transient protection (D2) - and as well D1 so that DESAT pin doesn't exceed VDD pin voltage

0 Yuhao Wang 4 months ago in reply to Sasikala Thangam

TI__Prodigy 330 points

Hello Sasikala

If necessary, can D1 be replaced with a voltage regulator tube? "Adjust resistor R1" or "add D4 voltage regulator tube" to adjust the desaturation trigger threshold, which one do you recommend more?

0 Sasikala Thangam 4 months ago in reply to Yuhao Wang

TI__Expert 5520 points

Hi Yuhao,

We have not done enough study with voltage regulator tube (VRT). I am curious to understand the reason for using VRT instead of D1 /D4 diodes?

DESAT circuit is very sensitive due to high dv/dt across the power module. To sense SC event appropriately, it will be good to do some simulation study before planning the VRT solution.

Thanks

Sasi

Power management

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UCC21750-Q1: desat