EE 321 Lab

Read the lab before answering these questions.

1. Find the gain for the circuit in figure 1. Use this formula. The gain is approximately equal to the ratio RC / RE. This is because vin controls ve = ie RE and because ic approx ie.

2. Consider the emitter follower in figure 2.

a) With VB = 0 V, find the bias currents. Use these to find re for the transistor model.

b) Find the input and output resistance of this circuit. The formulas are given in parts 5 and 6. Assume a beta of 200.

3. Consider a source, an amplifier, and a load (as was done in chapter 1). The source is a sine wave with a 1 V amplitude and a source resistance of 10 k. The amplifier has a voltage gain of 1, an input resistance and an output resistance as found above. The load is 220 ohms.

a) What is the output voltage if the load is connected directly to the source?

b) What is the output voltage if the source is connected to the input of the amplifier and the load to its output?

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