Common Gate Amplifier
In this circuit, input is applied between source and gate and output is taken between drain and gate.
In CG Configuration, gate potential is at constant potential. so, increase in input voltage Vi in positive direction increase the negative gate source voltage. Due to ID reduces, reduces, reducing the drop IDRD. Since VD= VDD-IDRD, the reduction in ID results in an increase in output voltage.
1. Input Impedance (Zi)
After substituting and simplification,
2. Output Impedance Zo
3. Voltage gain (Av)
Table summarizes the performance of common gate amplifier