47.3.4. Voltage Gain Calculation

Try these first

1. 1.

   What does voltage gain represent in an amplifier?

   Hint

   Think about how an amplifier enhances signals.

2. 2.

   How is transconductance (g_m) calculated?

   Hint

   Consider the currents and voltages related to the transistor.

3. 3.

   What is the formula for voltage gain?

   • A_v = V_out / V_in
   • A_v = V_in / V_out
   • A_v = R_out / R_in

   Hint

   Think about how the amplifier transforms the input signal.

4. 4.

   True or False: A voltage gain of 1 indicates no amplification.

   • True
   • False

   Hint

   Remember what a buffer does to a signal.

5. 5.

   Calculate the voltage gain and input impedance for a common collector amplifier given: β = 120, I_C = 1 mA, and r_o = 150 kΩ.

   Hint

   Convert I_C to g_m first.

6. 6.

   In a scenario where the load capacitance increases and source resistance is significant, analyze how this affects the bandwidth of the amplifier.

   Hint

   Remember f_cutoff = 1 / (2πRC); how do varying R and C affect this?