66.3.1. Limitation of Voltage Gain

Try these first

1. 1.

   Identify one role of the load resistor in a CE amplifier.

   Hint

   Think about how the resistor interacts with current.

2. 2.

   What is transconductance (g_m)?

   Hint

   Consider how it influences gain.

3. 3.

   What is the primary limitation of voltage gain in a CE amplifier?

   • The load resistance
   • The supply voltage
   • Transistor type

   Hint

   Consider the role of resistance in voltage division.

4. 4.

   True or False: The voltage gain of a common source amplifier is typically higher than that of a common emitter amplifier.

   • True
   • False

   Hint

   Reflect on the gain values discussed.

5. 5.

   Assume a common emitter amplifier has a load resistor of 1.5 kΩ and the DC supply voltage is 12V. If the thermal voltage is 26 mV, derive the maximum theoretical gain for this configuration.

   Hint

   Make sure to convert thermal voltage correctly and look at the concept of maximum gain.

6. 6.

   Propose a design modification for a common source amplifier experiencing low voltage gain. Detail how you would implement an active load and its expected impact.

   Hint

   Think about why using an active element can affect gain positively.