Electronics & Software – Tips & Guide


When is it good to use N MOSFET and when do you use P MOSFET?

When is it good to use N MOSFET and when do you use P MOSFET?


n are well suited when the voltage is pulled down through a load, while channel p is suitable for when the voltage is pulled up through a load.

n-mosfets usually have more products to gain bandwidth. This is a useful consideration for analog circuits. other than that depends on the need for a particular application

well, there are an indefinite number of configurations that you can design for mosfets n or p practical and effective, but you can simply put any circuit requiring an entry to very high impedance and therefore very ua) at the stage of driving and n types intrinsically have a bandwidth greater than p. . Thus, you would choose the type n for front receivers for a wide range and frequencies ranging from hf to uhf to microwaves and type p for biomedical instrumentation such as eegs or ekgs. . . hope this throws a little light

generally depends on how you want to pair them. If you connect a pmos drain in parallel with a nmos drain, you get a common stage amplifier. but if you use a nmos source for a nmos drain, you get a source follower. similar concept applies to the cmand and the doors that you see in digital logic, if you have pmos transistors with a voltage input connected in series, the nmos transistors must be connected in parallel for a nor operation, and vice versa for nand.

In general, nmos works better than its pmos counterparts because their mobile charge carriers are electrons, which move faster than holes (lack of electron) compared to a pmos. On the other hand, pmos transistors are much more economical and easier to manufacture.

As a general rule, if you work with a signal that is near or referenced to the most positive source, you use a p-channel. on the other hand, you use channel n when working with a signal that is near or referenced to the most negative power supply (usually ground). If the signal goes from positive to negative, it depends on how you want to change your load. If one side of your load is connected to the most positive power supply, you would use a channel to switch the other side of the load to the ground. if one side of the load is connected to ground, then you would use channel p to switch the other side to the power supply.

These are just general guidelines. There are many different ways to design circuits using different components. I’m sure someone can find a lot of counter-examples; but counterexamples would not necessarily invalidate the general guidelines.

a common use of mosfets is to use them as switches to turn lights, motors, etc., for this you need to know if the load will be grounded to work (the positive load terminal is already connected to load) positive) or switched to positive mode (negative charge terminal already connected to earth). it is referred to as high or low side switching, the switch being either low (between load and earth) or high (between the positive supply and the load).

The simplest way to use a single transistor with a low side switch is to use an n-type transistor (bipolar type npn or n mosfet). a positive base signal (or gate) allows the current of the load to flow through the ground, from the collector to the emitter (or from the drain to the source).

for a high-side switch, use a p-type transistor (pnp bipolar type or p mosfet). a voltage lower than the maximum positive voltage at the base (or gate) will circulate the current, positive through the emitter of the transistor, out of the collector to the positive charge (or positive supply, the source to drain, then positive charge).