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Can we use MOSFET as BJT?
The BJT is a bipolar junction transistor whereas MOSFET is a metal oxide semiconductor field-effect transistor. BJT’s are used for low current applications, whereas MOSFET is used for high power applications. Nowadays, in analog and digital circuits, MOSFETs are treated to be more commonly used than BJTS.
Should I use a MOSFET or BJT?
BJTs are much more suitable than MOSFETs for driving low-power LEDs and similar devices from MCUs. MOSFETs are better for high-power applications because they can switch faster than BJTs, enabling them to use smaller inductors in switch-mode supplies, which increases efficiency.
Why are MOSFETs better than BJT?
mosfet is much faster than bjt because in a mosfet, only majority carriers are the current. the device switches much faster than bjt and is therefore used for switching smps power. thus making the mosfet very ideal for amplifier circuits. mosfets are less noisy than bjts.
Can a MOSFET be switched on with a BJT base?
For mosfets this is not true, in other words mosfets gate which is equivalent to BJT base, require minimal current to switch ON, regardless of the drain current (drain pin of mosfet is equivalent to collector pin of BJT). Having said this, although the current is not the deciding factor for switching a mosfet gate, voltage is.
How to drive a MOSFET from a low current PIN?
My intention is to drive a MOSFET (say, a IRF840 or some logic-level) from a low-current (<10mA) SoC output pin. Using appropriate resistors from gate to pin and ground, this works… but the gate voltage change could be faster. So I considered putting a NPN (to VCC) & PNP (to GND) BJT between the pin and FET
Can a CMOS driver drive a FET gate?
You can buy a CMOS driver that drives a FET gate with several amps, for less than 1£$Euro. MOSFETS are voltage triggered and therefore they are perfect as they are with your microcontroler or SOC, as long as you use a pull-down resistor to pull the input to ground, you should be fine.
What kind of resistor do I need for MOSFET gate?
The pulldown resistor about 100 Ohm should be inserted from BJT emitters to GND to ensure mosfet’s off-state, because the PNP does not pull down effectively under +0,7 V. Additionally a few Ohm damping resistor inserted just into mosfet’s gate terminal should prevent some ringing caused by capacitance and wire inductance.