Common emitter transistor amplifier

May 26, 2012

jmher0403

Rc= 5k ohm
R1=100k ohm
R2= 27k ohm
Re=3.3k ohm
beta=200
Vs=12.7V

Vce= 0.3V at saturation

With no signal applied, dc voltage btw collector ans ground measured as 7.7V

Calculate the transistors base,emitter,collector currents

Ive only come across problems with transistor in linear region so I am confused where to start as I learned that Ib=Ic/beta no longer valid.

Please help.

Last edited: May 26, 2012

May 26, 2012

rude man

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Schematic diagram?

1. What is a common emitter transistor amplifier?

A common emitter transistor amplifier is a type of electronic circuit that uses a bipolar junction transistor (BJT) to amplify a small input signal and produce a larger output signal. This type of amplifier is characterized by having the emitter of the transistor connected to a common ground, while the input signal is applied to the base and the output signal is taken from the collector.

2. How does a common emitter transistor amplifier work?

A common emitter transistor amplifier works by using the transistor's ability to amplify a small change in current at its base to produce a larger change in current at its collector. This is achieved through the use of biasing resistors, which set the operating point of the transistor, and coupling capacitors, which allow the input and output signals to be coupled to the transistor without affecting the DC bias.

3. What are the advantages of a common emitter transistor amplifier?

One of the main advantages of a common emitter transistor amplifier is its high voltage gain, which allows it to amplify weak signals and produce a larger output. It also has a high input impedance, which means it does not draw a significant amount of current from the input signal source. Additionally, it is relatively easy to design and has a wide frequency response.

4. What are the limitations of a common emitter transistor amplifier?

One limitation of a common emitter transistor amplifier is its low output impedance, which can cause issues with signal distortion. It also has a limited bandwidth, which means it may not be suitable for amplifying high-frequency signals. Additionally, it requires careful biasing and can be sensitive to temperature changes, making it less stable than other types of amplifiers.

5. How is a common emitter transistor amplifier used in practical applications?

Common emitter transistor amplifiers are commonly used in audio applications, such as in amplifiers for music systems and guitar amplifiers. They are also used in radio frequency (RF) circuits, such as in radio receivers and transmitters, and in electronic devices like oscillators, filters, and inverters. In general, they are used whenever a small input signal needs to be amplified to a larger output signal.