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The emitter of a bipolar transistor (junction or point contact type) emits charge carriers(electrons in an NPN, holes in a PNP) through the base towards the collector.
Wiki User
∙ 10y ago
Wiki User
∙ 11y agoMost of the time emitter resistors are used to set the bias point of the transistor. Occasionally emitter resistors may act as fast blow fuses to protect a power transistor. In series linear voltage regulators an emitter resistor on each pass transistor to the regulated node is there to equalize current sharing between the pass transistors.
In other words it depends on the circuit design.
Wiki User
∙ 11y agoFor thermal stabilization...
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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.
Why we use emitter resistance in circuits?
The emitter resistor is connected to ground(in the case of an rc coupled amplifier).Also input signal applied at the base is grounded.Then the emitter resistor forms a feedback to the input signal (through the ground return path).So emitter resistor is also called feedback resistor.
What is swamp resistor?
Resistor placed in the emitter lead of a transistor circuit to minimize the effects of temperature on the emitter-base junction resistance.
What is the effect of emitter resistance in common emitter amplifier?
The gain of a common-emitter amplifier is collector resistor divided by emitter resistor, or hFe, whichever is less. Since hFe depends on temperature, designing the amplifier to be dependent on resistance ratio makes it more stable. As such, the emitter resistance serves to stabilize the amplifier.
What is effect of an unbypassed resistor on the common emitter amplifier circuit?
An emitter resistor in a common emitter circuit will cause the stage to experience the effects of degenerative feedback if it is unbypassed. The degenerative feedback reduces gain. This is probably the primary effect in the described circuit.
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.
Why we use emitter resistance in circuits?
The emitter resistor is connected to ground(in the case of an rc coupled amplifier).Also input signal applied at the base is grounded.Then the emitter resistor forms a feedback to the input signal (through the ground return path).So emitter resistor is also called feedback resistor.
What is swamp resistor?
Resistor placed in the emitter lead of a transistor circuit to minimize the effects of temperature on the emitter-base junction resistance.
What is the difference between a CB amplifier and CE and emitter-follower?
I think you mean a common emitter amplifier, which is an amplifier of voltage. Emitter-follower or common collector amplifiers are used to match impedances, or to amplify power or current. The emitter-follower is a type of common emitter circuit that has a resistor between the emitter and ground. The output signal is taken from the point between the emitter and its resistor.
What is the effect of emitter resistance in common emitter amplifier?
The gain of a common-emitter amplifier is collector resistor divided by emitter resistor, or hFe, whichever is less. Since hFe depends on temperature, designing the amplifier to be dependent on resistance ratio makes it more stable. As such, the emitter resistance serves to stabilize the amplifier.
What is effect of an unbypassed resistor on the common emitter amplifier circuit?
An emitter resistor in a common emitter circuit will cause the stage to experience the effects of degenerative feedback if it is unbypassed. The degenerative feedback reduces gain. This is probably the primary effect in the described circuit.
How emitter resistor provide more stabilization?
The emitter resistor places limits on the required gain, and temperature stabilizes the transistor. Without it, gain is hFe, but that is variable, temperature dependent, and subject to thermal runaway. With it, gain is predictable (collector resistor divided by emitter resistor, though limited by hFe), and temperature stabilized (so long as both resistors have the same temperature coefficient, and so long as the hFe margin is maintained).
What is the output resistance of common emitter amplifier with emitter resistor and without bypass capacitor?
Without a bypass capacitor it is just equal to Rc
How emitter bypass resistor stabilizes the amplifier against temperature?
In the common emitter (Class A) amplifier design of a BJT, gain is collector resistance divided by emitter resistance, or hFe, whichever is less. If the emitter resistance is zero, then gain is hFe. In this configuration, gain is unstable, because hFe is temperature dependent. In fact, under certain circumstances, a BJT can experience thermal runaway. The emitter resistor (along with the collector resistor) places a limit on the expected gain of the stage. If, for example, you design with a ratio of 10, then you expect a gain of 10. If hFe is 25-100, gain is still 10.
Define current gain of a common emitter configuration?
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.
What do you mean by emitter bypass capacitor?
a capacitor that bypasses a BJT's emitter bias resistor so the emitter is at AC ground but has a DC bias voltage on it to set operating conditions. without the bypass, the bias would not stay constant.
What is the function of an emitter?
emitter collects output current produced in resister Wrong. An emitter in a semiconductor emits majority current carriers (electrons or holes) into the junction between it and the base..
