What is the function of PNP transistor?

PNP transistors are used to source current, i.e. current flows out of the collector. PNP transistors are used as switches. These are used in the amplifying circuits. PNP transistors are used when we need to turnoff something by push a button.

Which transistor is best?

Best Transistors: BJTs

• #1 NPN – 2N3904. You can find most often NPN Transistors in low-side switch circuits.
• #2 PNP – 2N3906. For high-side switch circuits, you need a PNP style BJT.
• #3 Power – TIP120.
• #4 N-Channel (Logic Level) – FQP30N06L.

What is the difference between NPN and PNP transistors and their working?

One of the major difference between the NPN and PNP transistor is that in the NPN transistor the current flow between collector to emitter when the positive supply is given to the base, whereas in PNP transistor the charge carrier flows from the emitter to collector when negative supply is given to the base.

What is meant by PNP and NPN?

NPN stands for Negative, Positive, Negative. Also known as sinking. On an IO Module, an NPN input, when undriven is pulled down to be in a low state, GND ( or reference voltage level e.g. V-). PNP stands for Positive, Negative, Positive. Also known as sourcing.

How do I know which transistor to use?

In choosing a suitable switching transistor:

1. The transistor’s maximum collector current must be greater than the load current.
2. The transistor’s maximum current gain must be at least 5 times the load current divided by the maximum output current from the IC.

What is the most common PNP transistor?

The 2N2907 is an equally popular PNP transistor complementary to the 2N2222. The 2N3904 is an NPN transistor that can only switch one-third the current of the 2N2222 but has otherwise similar characteristics.

What is the difference between NPN and PNP proximity sensors?

The PNP and NPN sensors are 3-wire DC devices. The difference is in the type of transistor used in the sensor. The PNP device has 2 power control leads, one connected to the positive one, the other negative. The third thread connects to the load. The PNP and NPN sensors are 3-wire DC devices.

What is NPN or PNP?

NPN stands for Negative, Positive, Negative. Also known as sinking. On an IO Module, an NPN input, when undriven is pulled down to be in a low state, GND (or reference voltage level e.g. V-). PNP stands for Positive, Negative, Positive.

How does NPN transistor work?

The NPN transistor is designed to pass electrons from the emitter to the collector (so conventional current flows from collector to emitter). The emitter “emits” electrons into the base, which controls the number of electrons the emitter emits.

How does a PNP transistor work?

PNP Transistor. A PNP transistor receives positive voltage at the emitter terminal. The positive voltage to the emitter allows current to flow from the emitter to the collector, given that there is negative current to the base (current flowing out of the base to ground).