• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 240 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

Original question:

UCC21520-Q1: Shoot though prevention

UCC21520-Q1: Require IC with shootthrough capability

Amarendra Mishra5
Prodigy 20 points
Part Number: UCC21520-Q1

I am going to use the IC as a gate driver for mosfets in a full bridge dc-dc converter (boost mode).
This requires some shoot through time in order to build up inductor current to boost voltage.
What will happen if I try to turn on both mosfets on the same leg at the same time using the above driver?

Suggest a separate part in case this IC does not fulfill the above purpose.

  • 0
    TI__Mastermind 33340 points

    Hello Amarendra,

    When both inputs are asserted, the output behavior of UCC21520-Q1 depends on the configuration of the DT pin:

    • If the DT pin is floating, or programmed with a resistor to ground RDT of any size, the dead time interlock will be asserted and neither output will activate.
    • If the DT pin is connected to VCCI, the dead time interlock is bypassed, and both outputs will activate.

    For your application, the UCC21520-Q1 can support shoot-through, as long as the DT pin is connected to VCCI.

    Regards,

  • 0 in reply to Derek Payne
    Prodigy 20 points

    Thank you for your reply.
    Will the IC function if I externally short the VSSB and Signal GND? This is because I don't require isolation for my purpose.

  • 0 in reply to Amarendra Mishra5
    TI__Mastermind 33340 points

    Amarendra,

    The IC will function when VSSB and signal GND are shorted. Since the outputs are isolated both from each other and from the input, UCC21520-Q1 can be used with any combination of VSSA, VSSB, and GND shorted together.

    If the high current path shares a ground with the signal GND, we recommend placing small RC filters on the inputs, and tying any unused inputs to GND or VCCI as needed, to help mitigate the effects of ground bouncing and to prevent false turn-on or turn-off. Section 9.2.2.1 of the datasheet discusses the RC input filter considerations.

    Regards,