What do you need to know about bipolar junction transistors?

Bipolar Junction Transistors (BJT) Transistor Basics •  A Bipolar Junction Transistor is a three layer (npn or pnp) semiconductor device. •  There are two pn junctions in the transistor. •  The three layers are called the emitter, base and collector. 2 Transistor Basics

What does IIES stand for in bipolar junction transistors?

IIEs=e− (1.1) Due to the large differences in the doping concentrations of the emitter and the base regions the electrons injected into the base region (from the emitter region) results in the emitter current IE.

What are the different types of BJT transistors?

The BJT is a three terminal device and it comes in two different types. ThenpnBJT and the pnpBJT. The BJT symbols and their corresponding block diagrams are shown on Figure 1. The BJT is fabricated with three separately doped regions. The npn device has one p region between two n regions and the pnp device has one n region between two p regions.

How many PN junctions are there in a transistor?

• There are two pn junctions in the transistor. • The three layers are called the emitter, base and collector. • The base is lightly doped and sandwiched between the collector and the emitter. The collector is moderately doped and the emitter is heavily doped.

What is the common collector configuration for a BJT transistor?

19.  Common Collector Configuration Vi Vo Ic Ie Ib RE RB VBB VCC The input is on the base and the output is on the emitter. 20. Transistor Testing Checking the forward- biased base-to-emitter junction of an npn transistor Checking the reverse- biased base-to- collector junction of an npn transistor.

Why are the MOSFET transistors simpler to drive?

The MOSFET transistors are simpler to drive because their control electrode is isolated from the current conducting silicon, therefore a continuous ON current is not required. Once the MOSFET transistors are turned-on, their drive current is practically zero.

What does bias do in a DC transistor?

Bias  An electrical, mechanical or magnetic force applied to a device to establish a desired electrical or mechanical reference level for its operation.  Is a DC voltage or current that sets the operating point for amplifying the AC signal 24. Recall the following basic relationships for a transistor: 25.