This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCC21732-Q1: Response Time for DESAT Protection Configuration

Part Number: UCC21732-Q1
Other Parts Discussed in Thread: UCC21732, UCC21750


I'm trying to use UCC21732 in my design with DESAT protection configuration shown as Section in the datasheet. However, the datasheet seems only provide the delay information of OC protection configuration which is shown as the Figure 38 in Section 7.5.1. So I'm just wondering in DESAT case, what's the response time of protection and the definition of the start of that delay as the signal to OC pin is different from the OC case (it will not start with a nearly-zero value)? 



  • Pengkun,

    The timing is actually very similar to UCC21750, just without leading edge blanking time. Blanking time is set by your resistors and your capacitor value. Because the OC pin doesn't generate its own current source to charge the blanking cap, you need to use resistor to VDD to charge this, but the current is not virtually linear as tblk*Idesat=C*V

    TIming diagram of DESAT w/ OC, as well as calculation copied below

    We have a calculator sheet to help calculate T_BLK for DESAT w/ OC config located here, strongly recommend to try it as it will aid the design.

    If this answers your question, pleas press the green button.