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UCC21750: Gate voltage ripple failure of UCC21750/21732 Gate driver borad

Part Number: UCC21750

To whom this may concern,

Hello.I truly apologize for this sudden e-mail.

My name is Shinichi Hiroshige from Toshiba Electronic Devices & Storage Corporation.

We are testing SiC-MOSFET module (Toshiba MG600Q2YMS3) usinig UCC21750/21732 (TI) gate driver borad.

We try double pulse test for mesurement switching charactoristic.
But 2nd pulse output from gatedriver board is unstable.
We can't try switching test of target voltage and current.

Current situation:VDS=300V/ID=150A

What do you think cause 2nd pulse output is unstable?

We tried disable DESAT curcuit, but similar results were obtained.

Best regards


Toshiba Electronic Devices & Storage Corporation

Semiconductor Applocation Engineering center

Industial High Power Device Application Engineering Dept.


Shinichi Hiroshige


  • Hello Shinichi-san, 

    No worries, we are always here to help Slight smile

    Upon reviewing the waveform you provided, I was wondering if you can answer the below questions to help us understand the problem better: 

    • How is the low side driver turned off during this test? 
    • What probe was being used to measure Vds and Id? Since I want to understand if the noise below is probe ringing or actual system noise. 
    • What's the voltage level that's being fed to IN+? Looks like ~4V? 
    • How reproducible is this issue? Have you tried switching to another EVM and see if it resolved the issue? 

    Also, can you perform the following actions so we can get some more waveforms to look at: 

    • Make sure the IN+ high voltage is 5V for the following measurements
    • Measure the RDY and nFLT voltage near the pin

    Thank you and I look forward to hearing back!