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UCC27524: What's the maximum switching frequency that UCC27524 can support?

Ted Zhang
Intellectual 2280 points
Part Number: UCC27524

How to calculate the maximum switching frequency that a gate driver can support? Is it related to the power dissipation that the device can withstand?

Let's say using UCC27524 as the gate driver in a boost controller, input voltage: 12V, output 30V/2A, how to estimate the maximum switching frequency with the UCC27524 in this case according to datasheet?

Thanks!

  • 0
    TI__Genius 12990 points

    Hi Ted,

    Thanks for your question and good to hear from you!

    Max switching frequency depends on max power dissipation (which is about 900mW for UCC27524 in room temp). What also limits the max switching frequency are things like minimum input pulse, delay and distortion. Lets say you want to keep power dissipation down by setting VDD a bit lower to 7V you can also do this by changing load and frequency values. In fact, with a 10nF load on both channels at the same time when you sweep frequency by a factor of 10 going from 100khz to 1Mhz to 10Mhz, the power dissipation changes proportionally 14mW to 140mW to 1400mW. Holding frequency constant (10Mhz) It actually happens to work out that when you sweep the load from 10nF to 1nF to 100pF the power dissipation goes from 1400mW to 140mW to 14mW. So you can see that With a gate resistor things get better however it will also lower rise time and the max frequency.

    The max switching frequency can be highly dependent on load. From the datasheet UCC27524 can do 7ns rise times with 1.8nF load. Using 20xTrise = Tperiod = 140ns = 7Mhz max switching frequency @ 1.8nF - This is possible while VDD is at lower voltages and smaller loads to keep losses down. Its important to note that with higher VDD brings more losses however the driver strength will increase, and will show optimal rise time values. The datasheet values are with 12VDD.

    Please let me know if this answers your question, and feel free to reach out if you need more help.

    Thanks,