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.

UCC27424-EP: Protection Diodes for UCC27423-EP, UCC27424-EP driving Gate drive transformer

Part Number: UCC27424-EP
Other Parts Discussed in Thread: UCC27423-EP,

I am driving a gate drive transformer (240uH) with the UCC27423-EP, UCC27424-EP gate driver IC outputs. Do the integral body diodes of the MOSFET outputs protect the outputs of the driver IC when switching inductive loads? The data sheet is nor clear. I actually make a H-bridge with 2 UCC27423-EP, UCC27424-EP outputs. Like a DC motor driver. This way I can generate positive or negative output voltage from a single bias supply. Do I have to use external clamp diodes from the driver output to rail and ground  to protect from Ldi/dt? Please advise.

Thank you.


  • Jim,

    Thanks for reaching out.

    Yes, I would suggest the use of external clamp diodes to protect the device.  High di/dt occurs in the output loop: during turn-on and turn-off transients, which will induce significant voltage transients on the output pin of the driver device; especially with an inductive load.


    Aaron Grgurich

  • Thanks for the reply Aaron. The peak current is about 1A . I would think a 3A low voltage Schottky clamp diodes like used in snubber circuits should be sufficient. Please advise.


  • Jim,

    No problem!

    Yes, that diode should work!  We often use the BAT54S diode for protection, because it includes both diodes in one package.

    I hope this answers your question!  If so, please press the green button.  Otherwise, feel free to follow up!


    Aaron Grgurich