TPS43060: TPS43060 MOSFET select question

NObody

Expert 1100 points

Part Number: TPS43060

Hi, All：

As below picture that show IGD must less 50mA.

I have a issue after run webench as below file.webench_design_2047837_188_675151061.pdf

I Calculate IGD is over than 50mA, Is it ok??

If yes, May I choose a MOSFET that Qg = 42nC and used for high & low side MOSFET?

over 7 years ago

0 Garrett Roecker over 7 years ago

TI__Mastermind 21720 points

Hello,

When I do the calculation based on the design I get a much different answer.

The switching frequency of the design is 50kHz. The M1 has a gate charge or about 60nC while M2 has a gate charge of about 55nC.

Following the calculation IGD = (55nC+60nC)*50kHz =5.75mA. The MOSFETs selected should be okay.

-Garrett

0 NObody over 7 years ago in reply to Garrett Roecker

Expert 1100 points

Hi, Garrett:

Thanks for your reply soon.

I used error freq. to calculation.

another question, If set high switching frequency, We must choose low Qg MOSFET, right??

If I want used two 42nC MOSFET, I can't set TPS43060 freq. to 766KHz, Am I right??

0 Garrett Roecker over 7 years ago in reply to NObody

TI__Mastermind 21720 points

Hello,

That is correct. The gate driver current must be less than 50mA. This helps to ensure proper operation of the TPS43060 over the entire specified operating range.

-Garrett

0 NObody over 7 years ago in reply to Garrett Roecker

Expert 1100 points

Hi, Garrett
Got it, Thanks

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TPS43060: TPS43060 MOSFET select question