amplification factor
applications of common source amplifier
Configuration Voltage Gain Current Gain Input Resistance Output Resistance Common- Source AV >1 - ∞ Moderate to high Source-Follower AV ≈ 1 - ∞ Low Common- Gate AV > 1 Ai ≈ 1 Low Moderate to high Both the common-gate and common source has voltage gain of greater that 1 compared with the voltage gain of source- follower which is less than or approximately equal to 1 . The input resistance of both common-source and source follower is high typically ranges from kilo ohms and above while common-gate has a low input impedance ranges from hundred ohms or below. The output resistance of both common-gate and common-source are dominated by RD while source follower has low output impedance and is not dominated by RD
The small signal model for the common source FET can be used for analysing the basic FET amplifierconfigurations:(i)common source(CS),(ii)commondrain(CD) or source follower,and(iii)common gate(CG). The CS amplifier which provides good voltage amplification is most frequentlyused.The CD amplifier with high input impedance andnear-unity voltage gain is used as a buffer amplifier and the CG amplifier is used as a high frequencyamplifier.The small signal current-sourcemodel for the FET in CS configuration and the voltage source model can be derived by finding the Thevenin'sequivalent for the output part of amplificationfactor,drain resistance andtransconductance/mutual conductance of the FET.
• High Input Impedance Amplifier. • Low-Noise Amplifier. • Differential Amplifier. • Constant Current Source. • Analog Switch or Gate. • Voltage Controlled Resistor. • JFET as a Switch • JFET as a Chopper • JFET as a Current source • JFET as a Amplifier • JFET as a Buffer
An independent source is a source that produce constant currents and voltage. Dependent sources are voltage sources that depend on a voltage somewhere else in the network.
the same amount as the drain
Yes, the common source amplifier is out of phase. It inverts the input signal, meaning that when the input voltage increases, the output voltage decreases, and vice versa. This phase shift is a characteristic feature of common source configurations in field-effect transistors (FETs) and bipolar junction transistors (BJTs).
applications of common source amplifier
The voltage gain of an amplifier is determined by several key factors, including the amplifier's design and configuration (such as common emitter or common source), the values of its components (like resistors and capacitors), and the characteristics of the active devices (transistors or operational amplifiers) used. Feedback mechanisms, both negative and positive, can also significantly influence the gain by stabilizing or enhancing it. Additionally, the load impedance connected to the amplifier affects its voltage gain, as it interacts with the output stage of the circuit.
A low load resistance in a common-source amplifier can significantly reduce the overall voltage gain because it introduces a larger voltage drop across the load, decreasing the output voltage. The voltage gain (Av) is influenced by the load resistance (RL) since it is part of the voltage divider formed with the output resistance of the transistor. When RL is low, the effective output impedance decreases, leading to a lower gain. Additionally, a low load resistance can also increase the output current, potentially driving the amplifier into a nonlinear region, further affecting gain stability.
Configuration Voltage Gain Current Gain Input Resistance Output Resistance Common- Source AV >1 - ∞ Moderate to high Source-Follower AV ≈ 1 - ∞ Low Common- Gate AV > 1 Ai ≈ 1 Low Moderate to high Both the common-gate and common source has voltage gain of greater that 1 compared with the voltage gain of source- follower which is less than or approximately equal to 1 . The input resistance of both common-source and source follower is high typically ranges from kilo ohms and above while common-gate has a low input impedance ranges from hundred ohms or below. The output resistance of both common-gate and common-source are dominated by RD while source follower has low output impedance and is not dominated by RD
The small signal model for the common source FET can be used for analysing the basic FET amplifierconfigurations:(i)common source(CS),(ii)commondrain(CD) or source follower,and(iii)common gate(CG). The CS amplifier which provides good voltage amplification is most frequentlyused.The CD amplifier with high input impedance andnear-unity voltage gain is used as a buffer amplifier and the CG amplifier is used as a high frequencyamplifier.The small signal current-sourcemodel for the FET in CS configuration and the voltage source model can be derived by finding the Thevenin'sequivalent for the output part of amplificationfactor,drain resistance andtransconductance/mutual conductance of the FET.
• High Input Impedance Amplifier. • Low-Noise Amplifier. • Differential Amplifier. • Constant Current Source. • Analog Switch or Gate. • Voltage Controlled Resistor. • JFET as a Switch • JFET as a Chopper • JFET as a Current source • JFET as a Amplifier • JFET as a Buffer
Batteries provide a voltage difference.
The output impedance of a common source amplifier circuit is typically high. This is because the common source amplifier uses a resistor to provide biasing, which results in a high output impedance. However, this can be mitigated by using a current source instead of a resistor for biasing.
Batteries provide a voltage difference.
Impedence is synonymous with resistense. Greater the I, lesser the outputNo.First, it's *resistance* and *impedance*.Now, if the amplifier is a current amplifier, the above makes sense. (higher Zin, less Iin for a constant Vin).But if it's a purely voltage amplifier, it only responds to the input voltage, so the impedance (so long as it's not affecting the source/driving device) will have no effect on a purely voltage-amplifying amplifier.