Basic Requirements for MOSFET Driver Circuits

Post Time: May-21-2024

When designing a switching power supply or motor drive circuit using MOSFETs, most people consider the on-resistance, maximum voltage, maximum current, etc. of the MOSFETs, and many people consider only these factors. Such a circuit may work, but it is not the optimal solution, and this is not allowed as a formal product design. So what would be the requirements for a good MOSFET driver circuit? Let's find out!

(1) When the switch turns on instantaneously, the driver circuit should be able to provide a large enough charging current, so that the MOSFET gate-source voltage is quickly raised to the desired value, and to ensure that the switch can be quickly turned on and there is no high-frequency oscillations on the rising edge.

(2) In the switch on period, the drive circuit needs to be able to ensure that the MOSFET gate source voltage remains stable, and reliable conduction.

(3) Turn-off instantaneous drive circuit, need to be able to provide a low impedance path as possible, to the MOSFET gate source capacitive voltage between the electrodes of the rapid discharge, to ensure that the switch can be quickly turned off.

(4) Drive circuit structure is simple and reliable, low loss.