Transistor (IRF540N, N-Channel)

Features:

• Small signal N-Channel MOSFET
• Continuous Drain Current (I_D) is 33A at 25°C
• Pulsed Drain Current (I_D-peak) is 110A
• Minimum Gate threshold voltage (V_GS-th) is 2V
• Maximum Gate threshold voltage (V_GS-th) is 4V
• Gate-Source Voltage is (V_GS) is ±20V
• Maximum Drain-Source Voltage (V_DS)is 100V
• Turn ON and Turn off time is 35ns each’
• It is commonly used with Arduino, due to its low threshold current.
• To-220 package

IRF540N Equivalent

RFP30N06, IRFZ44, 2N3055, IRF3205

How to use IRF540N

Unlike transistors, MOSFETs are voltage controlled devices. Meaning, they can be turned on or turned off by supplying the required Gate threshold voltage (VGS). IRF540N is an N-channel MOSFET, so the Drain and Source pins will be left open when there is no voltage applied to the gate pin. When a gate voltage is applied these pins gets closed.

The below circuit shows how this mosfet behaves when the Gate voltage is applied (5V) and not applied (0V). Since this an N-Channel mosfet the load that has to be switched (in this case a motor) should always be connected above the drain pin.

When you turn on a Mosfet by supplying the required voltage to the gate pin, it will remain on unless you supply 0V to the gate. To avoid this problem, we should always use a pull-down resistor (R1), here I have used a value of 10k. In applications like controlling the speed of motor or dimming a light we would use a PWM signal for fast switching, during this scenario, the MOSFET’s gate capacitance will create a reverse current due to parasitic effect. To tackle this we should use a current limiting capacitor, I have used a value of 470 here.

Applications

• Switching high power devices
• Control speed of motors
• LED dimmers or flashers
• High Speed switching applications
• Converters or Inverter circuits