58.1.6. Small Signal Parameters and Voltage Gain Calculation

Try these first

1. 1.

   What is the formula for calculating transconductance (g_m)?

   Hint

   Recall the relationship between collector current and the thermal voltage.

2. 2.

   Define the term 'Operating Point.'

   Hint

   Think about when a transistor works efficiently in an amplifier.

3. 3.

   What does transconductance (g_m) indicate?

   • Control of output current by input voltage
   • Resistance in the output
   • Frequency response of the circuit

   Hint

   In your understanding, think of g_m as reflecting the sensitivity of the amplifier.

4. 4.

   True or False: A common collector stage always increases the voltage gain.

   • True
   • False

   Hint

   Evaluate the role of the CC stage in overall configurations.

5. 5.

   Given a CE amplifier with an input current of 20 μA and a beta of 150, calculate the collector current I_C and verify its effect on transconductance g_m for an assumed V_T of 26 mV.

   Hint

   Use the relationship between beta and collector current.

6. 6.

   Design a multi-stage amplifier using both CE and CC configurations, and explain the effect of each configuration on gain and bandwidth in a summary report.

   Hint

   Focus on the interactive role of both configurations in the cascading design.