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Original question:

UCC21222: gate driver IC burnt up after increasing DC link voltage beyond 100V.

UCC21330: Gate driver for SiC Mosfet Design

Sumit Singh
Prodigy 65 points
Part Number: UCC21330
Other Parts Discussed in Thread: UCC23525, UCC5350

Tool/software:

Hi,

I have made a PCB for UCC21330 with isolated Negative Bias with Two Iso-Bias Power Supplies (Murata DC-DC converter). I am only using output A for driving a high-side or a Low-side Mosfet. I have very little experience in PCB design. I request that you please look at my PCB design and suggest any improvements required. I have attached the KiCad file here

.Gate Driver_UCC21330.rar

Front CUback cu

Schematic

  • 0
    TI__Mastermind 23106 points

    Hi Sumit,

    If you only need one gate driver, you can use a single channel part like UCC23525. 

    However, if you use the UCC21330, make sure to leave the NC pin floating, not grounded. Sometimes these pins can be tied to internal nodes for pre-production testing.

    You should have one capacitor from Vdd straight across to Vss, which will protect the gate driver from transient overvoltage better than two series capacitors. You only need one set of the series capacitors to decouple the bipolar supply.

    51/2 ohms is a huge Rg value. Are you sure you need this much? Typical values are 5-10 ohms, and sometimes even lower is better for switching losses.

    Best regards,

    Sean

  • 0 in reply to Sean Cashin
    Prodigy 65 points

    Hi Sean,

    Thank you so much for your answer.

    Actually, I have followed the data sheet where, in an example of "Negative Bias with Two Iso-Bias Power Supplies," it was shown two series connected capacitors between VDD and VSS with ground in the middle, Is that not correct? Are the values of capacitors throughout PCB sufficient? is one set of capacitor between VDD and VSS enough? I have made a mistake in putting the value of Rg; it is indeed between 5 and 10 ohms. Can you please look at the PCB layout? Will it work? My DC link voltage is 1000 volts.

     

    Waiting for your reply

    Thanks

    Sumit Singh

  • 0 in reply to Sumit Singh
    TI__Expert 8686 points

    Hi Sumit,

    This capacitor configuration is for the negative bias using two isolated bias supplies.

    If this is not the case in your application, a capacitor between VDDx-VSSx is sufficient.

    As Sean stated before, we would recommend to use one of our single channel drivers if only 1 channel is being used.

    Let me know if you have any additional questions!

    Regards,

    Hiroki

  • 0 in reply to Hiroki Honda
    Prodigy 65 points

    Hi Hiroki,

    Thank you for your answer.

    My application needs  negative bias using two isolated bias supplies, so I have used this capacitor configuration. I am not finding any cheap simple single channel driver with an enable/disable function, and I already have this UCC21330, which is why I am using it. Can you suggest any single-channel driver IC with the same functionality? Can I not use the dual-channel driver as a single-channel driver?  Please look at my PCB layout. I am very new to PCB design and I need suggestions. My DC link is 1000 volts, and the switching frequency is 100 kHz. I have used a 2W Murata DC-DC converter with a bipolar output voltage supply (+15/-5V) (MGJ2D051505SC). 

     

    Thanks

    Sumit Singh

  • 0 in reply to Sumit Singh
    TI__Expert 8686 points

    Hi Sumit,

    Thank you for following up.

    Here is a device that could be a better fit: https://www.ti.com/product/UCC5350 

    UCC5350 is a single channel isolated gate driver which would save space on your board. The complimentary input can be used as a disable function.

    For the board layout, refer to section 10 on the datasheets for layout examples and tips.

    The layout guidelines will be good to check.

    From a first glance, your board layout looks to be okay. 

    Regards,

    Hiroki

  • 0 in reply to Hiroki Honda
    Prodigy 65 points

    Hi Hiroki

    Thank you for your suggestion. Next time, I will go for the single-channel gate driver. Since I have already purchased the UCC21330, I am planning to use it as a single-channel gate driver because of its low cost and simple functions. I just want to know if I can use the UCC21330 as a single-channel gate driver or not.

    Thanks 

    Sumit Singh

  • 0 in reply to Sumit Singh
    TI__Expert 8686 points

    Hi Sumit,

    Understood, thank you for the explanations.

    There will be no problems using UCC21330 as a single channel gate driver.

    Please feel free to ask any additional questions below.

    Regards,

    Hiroki