MOSFET gate resistor
The MOSFET is called one of the main powerful semiconductor devices in electronics, so on MOSFET gate is the terminal used to trigger the device.
In this post we discuss MOSFET gate resistor, selecting up a proper resistor for the MOSFET gate is a difficult task because MOSFET is a sensitive component to work with.
MOSFET gate resistor selection
- The main purpose of the gate resistor at the MOSFET is suppression of increasing current and reduction in output ringing.
- When we selecting a large value resistor, it will decrease the switching speed of MOSFET.
- This will cause power loss, reduction in performance, and potential heat issues.
- At the same time, a small resistor increases the switching speed of the MOSFET, which will cause susceptibility to voltage surge and oscillation and that will result from damages to the device.
- Therefore we need to select an optimal value for the gate resistor for the proper functions of MOSFET.
MOSFET gate resistor calculator
We already mentioned that the MOSFET gate resistor must have set an optimal value, the selection of resistor value for MOSFET will have to calculate in terms of the purpose,
One of the important purposes of gate resistor is only to slow things down by reducing gate driver current,
Igate = Vgate / (Rsource + Rgate + Rg)
The driving device will have a maximum driver current, you need to choose a minimum value of Rate, to ensure that value is never exceeded.
Rgate = Vgate / I(max)
This is the procedure to calculate the MOSFET gate resistor value.
Parallel MOSFET gate resistor
When we calculating gate resistors for a single MOSFET will be selected with the application of the circuit.
As when we select a gate resistor for parallel MOSFET, which need to consider the fact that particular circuit quantities will be doubled.
We calculate the gate resistor with the appropriate damping ratio, rise time, and overshoot.