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Do you need a transistor to drive a MOSFET?
So, all you need is a normal transistor-driven MOSFET circuit, and a normal microcontroller-driven LED circuit. Here’s an example of driving a MOSFET with a transistor: So Q2 is the output side of the opto-couper. R2 would be replaced by the input LED side of the opto-coupler and it’s current limiting resistor.
Can a microcontroller drive a MOSFET with an optocoupler?
Anything up to about 10 kHz should work OK./ For faster PWM a properly designed driver is required. As far as the MOSFET is concerned, an optocoupler is just a transistor. As far as the microcontroller is concerned, an optocoupler is just an LED.
What is the correct way of turning on a MOSFET?
A correctly calculated MOSFET turn-ON process ensures that the device is switched ON with optimal efficiency. While designing MOSFET based circuits you might have wondered what is the correct way of turning ON a MOSFET?
What is the threshold voltage of a MOSFET?
First of all we must realize that the threshold voltage, denoted as V GS (th) is not for circuit designers to worry about. To be precise, it is the gate voltage which causes the drain current of the MOSFET to cross a threshold level of 250 μA, and this is tested under conditions that might never normally transpire in practical applications.
When to use a p-channel MOSFET in a micro controller?
There are a couple of tricks to remember when using them. P-Channel MOSFETs are useful for switching positive supply of a target circuit on and off. Particular attention must be placed to the target circuit if the supply voltage is greater then the micro controller’s logic voltages.
What is the ideal Fet for a MOSFET?
Using Digikey’s parameter selection system let’s spec the “ideal FET for this and similar applications. 100V, 50A, logic gate (low turn on voltage, R d s ( o n) < 50 m Ω.