What is saturation voltage of transistor?

“Saturation” in a transistor switch circuit is achieved when the voltage across the collector/ emitter (VCE(sat)) is less than or equal to . 1 to . 3 volts – depending on the type of transistor. At that voltage point, the transistor appears to act like a simple SPST mechanical switch that has been closed (On).

What is meant by 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.

What is saturation voltage?

saturation voltage, collector-emitter (VCE(sat)) The voltage between the collector and emitter terminals under conditions of base current or base-emitter voltage beyond which the collector current remains essentially constant as the base current or voltage is increased. (Ref. IEC 747‑7.)

How is NPN calculated?

For an good NPN transistor, the meter should show a voltage drop between 0.45V and 0.9V. If you are testing PNP transistor, you should see “OL” (Over Limit). Hook the positive lead from the multimeter to the to the EMITTER (E) of the transistor. Hook the negative meter lead to the BASE (B) of the transistor.

Why VCE SAT is 0.2 V?

transistor vce voltage drop It is because both the junctions in the transistor are forward biased at saturation. Under this condition, for npn transistor the emitter to base voltage is ~+0.7V and than between the base to collector ~0.5V (base p, collector n).

Is VBE always 0.7 V?

The base emitter junction is a PN junction or you can consider that as a diode. And the voltage drop across a silicon diode when forward biased is ~0.7V. That is why most of the books write VBE=0.7V, for an NPN silicon transistor with forward biased emitter junction at room temperature.

What is PNP or NPN?

PNP = Switched Positive. NPN = Switched Negative. “Switched” refers to which side of the controlled load (relay, small indicator, PLC input) is being switched electrically.

Can I use PNP instead of NPN?

Generally, the PNP transistor can replace NPN transistors in most electronic circuits, the only difference is the polarities of the voltages, and the directions of the current flow. PNP transistors can also be used as switching devices and an example of a PNP transistor switch is shown below.

How do you know if a BJT is in saturation?

Monitor the collector-emitter voltage of your circuit with a DMM. If the reading is below 0.3V, the transistor is at saturation. Transistors are having saturation voltage range from 0.7V and below but for a circuit designed for hard saturation, the VCE will be lower.

How do you know if a transistor is NPN?

Connect the positive lead of the multimeter to the Base (B) of the transistor and connect the negative lead to the Emitter (E) of the transistor. If it is an NPN transistor then meter should show a voltage drop between 0.45V and 0.9V. If it is a PNP transistor, then it should display see “OL” (Over Limit).

What is difference between PNP and NPN transistor?

An NPN transistor has a piece of P-type silicon (the base) sandwiched between two pieces of N-type (the collector and emitter). In a PNP transistor, the type of the layers are reversed. NPN and PNP transistors have very similar schematic symbols. The only difference is the direction of the arrow on the emitter.

Why is VBE 0.7 V?