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The voltage gain of a common emitter transitor amplifier is (inverted) collector resistor divided by emitter resistor, unless this would exceed hfe or the transistor is operating in non-linear mode.

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Why more current amplification in common emitter?

A bipolar transistor can be used in different configurations in linear electronic design. Most well known is the common emitter CE configuration with a base current as input signal resulting in a collector signal multiplied by the current gain factor. The second configuration is known as the emitter follower or common collector configuration. Here the input signal is in the form of a voltage between the base and the common connection. The output signal is found in the form of a voltage at the emitter with a relative low output impedance. The voltage swing at the input is almost as large at the output where the input impedance equals the product of the current gain factor and the emitter resistance. The third configuration is known as common base CB. Here the input current at the emitter almost equals the output current at the collector. The current gain is nearly equal to 1.


What are the three basic transistor connection configuration modes?

The three basic transistor connection configuration modes are common emitter, common base, and common collector. In the common emitter configuration, the emitter terminal is common to both the input and output circuits, providing high voltage gain. The common base configuration has the base terminal common to both circuits, offering high frequency response but low voltage gain. Finally, the common collector configuration, also known as an emitter follower, provides current gain and high input impedance while maintaining unity voltage gain.


How does a transistor amplify in a common emitter configuration?

The base is excited by a very low current. That turns the transistor on so that a higher amount of current flow comes out.


In a common emitter transistor the primary purpose of a resistor connected to the emitter is to?

The emitter resistor in a common emitter configuration provides negative feedback to the transistor, reducing both its voltage gain and distortion.


Transistor as an amplifier common emitter configuration explanation using kirchhof's law?

Kirchoff's current law states that the current in every point in a series circuit is the same. In the case of a transistor in common emitter configuration, you can take advantage of that fact and state that the collector current is equal to the emitter current. The truth is somewhat different, because the gain of the transistor is not infinity, so the base current must be added to the emitter current. With a reasonably high gain, however, you can ignore the base current. Consider that the emitter voltage is related to the base voltage by the forward drop of the base-emitter junction, about 0.7 volts, and the collector and emitter currents are the same. Now look at the collector and emitter resistors. If the currents are the same, and the voltage across the emitter resistor is known, then you know the voltage across the collector resistor as well. This is an application of both Kirchoff's and Ohm's laws. The gain, then, of this amplifer is collector resistance divided by emitter resistance. It is an inverting amplier in this configuration. In some configurations, the emitter resistor is zero ohms. This does not mean the gain is infinity - it now means that the gain is limited by the gain of the transistor, which it is anyway - the emitter resistor is used to stabilize the gain and reduce dependency on individual transistor gains, which do vary.

Related Questions

For common collector configuration op current is?

output current is emitter current i.e.,Ie


What if base current is zero in a transistor used as an amplifier with common emitter configuration?

output current is zero


What is Current amplification factor in common emitter configuration?

comparerission between CB,CC&CE


Why more current amplification in common emitter?

A bipolar transistor can be used in different configurations in linear electronic design. Most well known is the common emitter CE configuration with a base current as input signal resulting in a collector signal multiplied by the current gain factor. The second configuration is known as the emitter follower or common collector configuration. Here the input signal is in the form of a voltage between the base and the common connection. The output signal is found in the form of a voltage at the emitter with a relative low output impedance. The voltage swing at the input is almost as large at the output where the input impedance equals the product of the current gain factor and the emitter resistance. The third configuration is known as common base CB. Here the input current at the emitter almost equals the output current at the collector. The current gain is nearly equal to 1.


What are the three basic transistor connection configuration modes?

The three basic transistor connection configuration modes are common emitter, common base, and common collector. In the common emitter configuration, the emitter terminal is common to both the input and output circuits, providing high voltage gain. The common base configuration has the base terminal common to both circuits, offering high frequency response but low voltage gain. Finally, the common collector configuration, also known as an emitter follower, provides current gain and high input impedance while maintaining unity voltage gain.


Why Common Emitter Configuration is most commonly used in amplifier circuits?

the common emitter configuration is most widely used in amplifer circuits because of its high voltage,current & power gain.the common emitter configuration is most widely used in amplifer circuits because of its high voltage,current & power gain.


How does a transistor amplify in a common emitter configuration?

The base is excited by a very low current. That turns the transistor on so that a higher amount of current flow comes out.


Which transistor configuration has the highest input impedance?

Common Emitter Configuration has maximum impedance.


In a common emitter transistor the primary purpose of a resistor connected to the emitter is to?

The emitter resistor in a common emitter configuration provides negative feedback to the transistor, reducing both its voltage gain and distortion.


Can you use CC configuration as an amplifier?

The Common Collector configuration amplifies current, by having the emitter voltage follow the base voltage, with an offset of the forward conduction voltage of about 0.7 volts, with a current gain of beta. (hFe)


Transistor as an amplifier common emitter configuration explanation using kirchhof's law?

Kirchoff's current law states that the current in every point in a series circuit is the same. In the case of a transistor in common emitter configuration, you can take advantage of that fact and state that the collector current is equal to the emitter current. The truth is somewhat different, because the gain of the transistor is not infinity, so the base current must be added to the emitter current. With a reasonably high gain, however, you can ignore the base current. Consider that the emitter voltage is related to the base voltage by the forward drop of the base-emitter junction, about 0.7 volts, and the collector and emitter currents are the same. Now look at the collector and emitter resistors. If the currents are the same, and the voltage across the emitter resistor is known, then you know the voltage across the collector resistor as well. This is an application of both Kirchoff's and Ohm's laws. The gain, then, of this amplifer is collector resistance divided by emitter resistance. It is an inverting amplier in this configuration. In some configurations, the emitter resistor is zero ohms. This does not mean the gain is infinity - it now means that the gain is limited by the gain of the transistor, which it is anyway - the emitter resistor is used to stabilize the gain and reduce dependency on individual transistor gains, which do vary.


Why common emitter configuration is mostly used for transistor as switch?

because in ce configuration value of input voltage requried to make the transistor on is very less value of the output voltage or output current