Proper power supply for this gate driver IC

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Xavier Pacheco Paulino

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I will use the gate driver configuration shown below:

Gate Driver datasheet
MOSFET Datasheet



As you can see, the 5V and 12V are isolated. I chose this AC/DC converter for the 5V supply. It's 1 Output 5V/3A. It will supply a STM32 and a Raspberry Pi.

I decided to step up the 5V to 12V using this Isolated Module DC DC Converter.

That module is just 1W/ 84mA max. My question is: Can it effectively supply the peak currents to charge gate capacitance using decoupling capacitors?

This what I think:
The 12V step-up module will supply an average current of I = Qxfs, where Q is the total charge of the mosfet and fs my pwm frequency. According to my mosfet datasheet the total charge is 160nC, my pwm frequency is 10 kHz. So I = 160nC * 10000 = 1.6 mA... am I right?
That means that my step up module is okay... right?
 

Hi,

The gate charge maths is right, 1.6mA.
 

yes, gate charge is high current but very short duration, so average current to drive gate is low....the spike of current to drive the gate will come from a small ceramic that you place near the gate driver
 

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