Fixed bias with emitter resistor, Electrical Engineering

Fixed bias with emitter resistor:

711_Usage.png

Figure: Fixed bias with emitter resistor

The fixed bias circuit is changed through attaching an external resistor to the emitter. This resistor establishes negative feedback which stabilizes the Q-point. From the voltage law of Kirchhoff, the voltage across the base resistor is

VRb = VCC - IeRe - Vbe.

From the law of Ohm, the base current is

Ib = VRb / Rb.

The manner feedback controls the bias point is like this. If Vbe is stay constant and temperature get increases, emitter current also increases. Though, a larger Ie increases the emitter voltage Ve = IeRe, in turn which decreases the voltage VRb across the base resistor. A lower base-resistor voltage drop decreases the base current that results in less collector current since Ic = ß IB. Collector current and emitter current are related through the Ic = α Ie with α ≈ 1, thus an increase in emitter current with temperature is opposed, and operating point is kept stable.

Posted Date: 1/10/2013 7:20:15 AM | Location : United States







Related Discussions:- Fixed bias with emitter resistor, Assignment Help, Ask Question on Fixed bias with emitter resistor, Get Answer, Expert's Help, Fixed bias with emitter resistor Discussions

Write discussion on Fixed bias with emitter resistor
Your posts are moderated
Related Questions

Registers A resister is  a group  of flip  flops  or binary  cells which holds  the binary information. Since  a binary cell  stores  one  bit of  information  an n bit  regis

How is EISA bus different from ISA bus? The Extended Industry Standard Architecture (EISA): it is a 32 bit modification to the ISA bus. Since computers became larger and had wi

A second-order process with one pole at the origin has the transfer function 3/(s(2s + 1)) Find the output as a function of time, for a unit step input change. Sketch the expected

To design a VI that can also be used as a Sub VI in another VI. The title of the VI will be Pulse Generator. The output from the VI will be of the type Analogue Waveform and

Q. Explain working of Ring Topology? Ring Topology: In ring topology, all user nodes are connected with physical path acting as links of a chain and last user node is co

Q. Give a block diagram for amodulo-5 binary ripple counter using JKFFs and draw its timing diagram.

Discuss the assembler directive of OFFSET with example. OFFSET: This is an operator to find out the offset (displacement) of a variable or process regarding the base

conclusion about electrical engireng??

Common-collector configuration:  The common-collector that is abbreviated CC transistor configuration is displayed in figure.  In this type of configuration, the collector is