19.1.6. Output Conductance

Try these first

1. 1.

   Define transconductance and explain its significance.

   Hint

   Think about the relationship between input voltage and output current.

2. 2.

   What is the output conductance in terms of collector current and collector-emitter voltage?

   Hint

   Recall the ratio definition.

3. 3.

   What does output conductance measure?

   • Sensitivity of collector current to V_CE
   • Sensitivity of base current to V_BE
   • Total resistance of the circuit

   Hint

   Think about what current behavior you want to study.

4. 4.

   True or False: Transconductance is defined as the slope of the I_C vs. V_BE curve.

   • True
   • False

   Hint

   Recall the definition discussed in class.

5. 5.

   A BJT has a collector current of 1mA at a particular Q-point. If the V_BE varies by 0.1V, calculate the transconductance assuming the collector current varies to 1.2mA.

   Hint

   Use the formula ΔI_C / ΔV_BE.

6. 6.

   Given a BJT with early voltage (V_A) of 100V, and the collector current increases from 10mA to 12mA as V_CE increases from 5V to 15V, determine the output conductance.

   Hint

   Recall how output conductance is defined with respect to I_C and V_CE.