Fixed bias with emitter resistor, Electrical Engineering

Assignment Help:

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.


Related Discussions:- Fixed bias with emitter resistor

Convolution, how to use tabular method to solve convolution problems

how to use tabular method to solve convolution problems

3rd year electrical/electronics project, I`m a 3rd year electrical engineer...

I`m a 3rd year electrical engineering student studying in Canada, and there is a new course they added in my university for 3rd year students called Engineering Project. from the

Abcd propagation , ABCD propagation of an optical ray through a system can...

ABCD propagation of an optical ray through a system can be explained by a simple 2_2 matrix. In ray optics, the characteristic of a system is given by the corresponding ray matrix

Can you explain twos complement division, Q. Can you explain twos Complemen...

Q. Can you explain twos Complement Division? 2's complement division is repeated 2's complement subtraction. The 2's complement of the divisor is calculated, and then added to

How does expert system works, How does Expert system works? System uses...

How does Expert system works? System uses a rule base and an inference engine together to simulate human reasoning whenever analysing a problem and arriving at a conclusion. To

Explain repetitive coverage of satellite, Q. Explain Repetitive coverage of...

Q. Explain Repetitive coverage of satellite? Due to repeated passes of the satellite over the same reach, data is repeatedly acquired. Therefore, comparisons of a dynamic pheno

Explain lda and daa instructions, Explain LDA, STA and DAA instructions ...

Explain LDA, STA and DAA instructions LDA copies the data byte into accumulator from the memory location particular by the 16-bit address. STA copies the data byte from the acc

Microprocessors, Microprocessors: We have learnt 8085 family of microp...

Microprocessors: We have learnt 8085 family of microprocessors. Initially, we understand basic components of a computer, 8085 microprocessor architecture and assembly language

Voltage divider with ac bypasses capacitor, Voltage divider with AC bypasse...

Voltage divider with AC bypasses capacitor: Figure: Voltage divider with capacitor The standard voltage divider circuit that is discussed above faces a drawback - A

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd