CSD16323Q3 gs resistor, is it must be needed?

Helen chen

Mastermind 40080 points

Hi,

Could you please tell me whether the resistor R17 connected between gs must be needed? Thanks!

BR,

Helen

over 8 years ago

0 Helen chen over 8 years ago

TI__Mastermind 40080 points

One more question: Could this resistor's value be as large as 499k. Because there're so many Logic signals and too small resistor value will affect the control signal level....

0 Brett Barr1 over 8 years ago in reply to Helen chen

TI__Mastermind 18200 points

What is your application? What frequency and voltage are you driving the FETs at?

0 Helen chen over 8 years ago in reply to Brett Barr1

TI__Mastermind 40080 points

This Mosfet is used at the power modules's output return, when the output current is higher than a certain level, it opens. So normally, it is always closed during normal working, drive voltage Vgs=5V.

0 Brett Barr1 over 8 years ago in reply to Helen chen

TI__Mastermind 18200 points

Helen,

Traditionally, people use an external resistor between gate and source to prevent unwanted turn on of the MOSFET due to static discharges in the even that the gate driver pin is left floating.

If this is a legitimate concern in your design, than yes it is ok to include that resistor. 500k ohm is a little high, usually these are on the order of 10k to 100k ohm, but 500k ohm should still work.

If you are not worried about a floating gate driver node however, this should not be necessary.

0 Helen chen over 8 years ago in reply to Brett Barr1

TI__Mastermind 40080 points

Clear, thanks! I prefer not to add this resistor into the schematic, because it will effect the voltage level of the Vgs.

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CSD16323Q3 gs resistor, is it must be needed?