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UCC23513: UCC23513 max switching freq. support

Part Number: UCC23513
Other Parts Discussed in Thread: UCC21540, UCC5320

Hi team,

I would like to check with you if UCC23513 can support 120KHz, duty cycle = 1~2% application? I see UCC23513 has 105-ns (maximum) propagation delay. 

with 120KHz, duty cycle = 2%, the SW ON time is between 1/120KHz * 1% = 83ns & 1/120KHz * 2% = 166ns, which is  close to the max propagation delay of UCC23513. I am wondering if there has some issue.

If UCC23513 can't be used, perhaps we can suggest customer to use UCC21540(A), which has 40ns max propagation delay.

thanks.

Best regards,

Yang

  • Hi, Yang,

    Ni hao!

    Propagation delay is shown in this figure:

    In some closed-loop systems (with feedback), the loop delay may be too large for the controller to handle.

    It could be a problem at very high frequency if the pulse-width is less than the propagation delay as you have stated.  Another choice would be UCC5320 which has shorter propagation delays than UCC23513.

    Let me know if you have further questions, Yang. Otherwise, please press the Green button.

    Best regards,

    Don

  • Hi Don,

    thanks for your help!

    Best regards,

    Yang