The base, being an n-type semiconductor will have electrons as its majority charge carriers. The emitter has a large concentration of holes. Let’s look at the path of current in a p-n-p transistor: p-n-p Transistor Since the base is very thin and lightly doped, it has very few majority carriers.
These majority carriers enter the base in large numbers. The emitter is heavily doped and has a large concentration of the majority carriers. The Base-collector junction is reverse biased.Let us now study the path of the current carriers in the junction transistor where – V CC = Power supply connected between the collector and base.V EE = Power supply connected between the emitter and base.The voltage between collector and base = V CB.The voltage between emitter and base = V EB.The circuit diagram for the same is as shown below:Īs can be seen above, the base is the common terminal for two power supplies whose other terminals are connected to the emitter and collector. The base-collector junction is reverse biased.The emitter-base junction is forward biased and.The Amplifying Capabilities of a Junction TransistorĪ junction transistor works as an amplifier when, Application of Junction Diode as a Rectifier.Junction Transistor as a Feedback Amplifier and Transistor Oscillator.Junction Transistor – Circuit Configurations and Characteristics.Classification of Metals, Conductors and Semiconductors.Browse more Topics under Semiconductor Electronics Materials Device And Simple Circuits Eventually, it became equally popular as a switch. It is also important to note here that junction transistor was invented to produce an enlarged copy of a signal – an amplifier. To understand the action of the transistor, it is important to consider the nature of depletion regions formed at these junctions. Hence, it collects most of the majority carriers supplied by the emitter.Īlso, in the case of a junction transistor, the depletion regions are formed at the emitter-base junction and the base-collector junction. It is larger than the emitter and is moderately doped. This segment is also on one side of the transistor. This segment is at the centre of the transistor. It has a moderate size and is heavily doped causing it to supply a large number of carriers for the flow of current. This segment is on one side of the transistor.
Let’s understand the three segments in detail: Emitter The arrowhead shows the direction of the conventional current in the transistor. The schematic symbols of both these transistors are as follows: p-n-p transistor: An n-type semiconductor (base) separates two segments of the p-type semiconductor (emitter and collector.Īs can be seen in both the figures above, all three segments have different thickness and doping levels.n-p-n transistor: A p-type semiconductor (base) separates two segments of the n-type semiconductor (emitter and collector).Depending on the number of n and p-type semiconductors in the transistor, they are of two types: These regions form two p-n junctions between them. A junction transistor has three doped regions – emitter, base, and collector.
0 kommentar(er)
