TPS56C215: Parasitic capacitance of Mosfet

Nini Zhong

Genius 13105 points

Part Number: TPS56C215

Hi team ,

can I ask what how much is the parasitic capacitance of high side and low side Mosfet ?

Best regards !

over 3 years ago

+1 Andrew Xiong over 3 years ago

TI__Expert 5470 points

Hi Nini,

That's related with the internal Mos design of the device and normally we won't share the information with customer. Why are those parameters needed?

Thanks,

Andrew

0 Nini Zhong over 3 years ago in reply to Andrew Xiong

TI__Genius 13105 points

Hi Andrew ,I want to check the oscillation frequency of SW ringing during DCM mode .

Is the fosc=1/(2πL(C1+C2)) ,or just C2 involved in the oscillation which means fosc=1/(2πL(C1+C2))?

0 Nini Zhong over 3 years ago in reply to Nini Zhong

TI__Genius 13105 points

The last equation is : fosc=1/2πLC2

0 Nini Zhong over 3 years ago in reply to Nini Zhong

TI__Genius 13105 points

If only C2 is involved in the LC oscillation , the circuit loop is the above one . Then the fosc=1/(2πLC2) .

I have tested the oscillation cycle , which needs to be checked if matching the equation .

Thanks a lot !

0 Andrew Xiong over 3 years ago in reply to Nini Zhong

TI__Expert 5470 points

Hi Nini,

Nice try. From my understanding and previous materials, it is related with C2. But I think you can have a try simply by adding a 470pF cap parallel with C1 (between SW and Vin pin) and see if the oscillation frequency will change.

Thanks,

Andrew

0 Andrew Xiong over 3 years ago in reply to Andrew Xiong

TI__Expert 5470 points

Hi Nini,

Let's discuss about this through email or call. I'll close this thread first.

Thanks,

Andrew

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TPS56C215: Parasitic capacitance of Mosfet