Experiment

  

Figure 5.4: Differential Amplifier for Experiment

1.

Construct the differential amplifier in Fig. 5.4.

2.

Measure the DC values at the collector of Q1 and Q2. Do the measured values agree with theoretical ones.

3.

Measure the DC value at the emitter of Q1 and Q2. Do the measured value agree with the theoretical one.

4.

Indicate the inverting and non-inverting output.

5.

Input an AC signal into Q1 of your circuit at midband frequencies (approximately 50kHz.) What is the single ended voltage gain of your circuit? (You may have to reduce the magnitude of your input signal with a voltage divider to obtain a signal which is small enough that does not clip. If you do use a voltage divider, remember to account for its output resistance, and the input resistance of the circuit, when calculating the gain of the circuit.)

6.

By driving the input with sources that have source resistances ranging from 1K to 100K, develop a way to measure the input resistance of the circuit. (Just put resistors ranging from 1K to 100K in series with your signal source.) Does your measured value agree with your theoretical calculation.

7.

By driving various AC coupled loads ranging from 1K to 100K, develop a way to measure the output resistance of the circuit. Does your measured value agree with your theoretical calculation.