Equipment:
You must make up a complete equipment list and have your instructor review it before you start.
 

Objectives:

• To verify the operating point for a MOSFET biasing network

• To verify the small signal performance for a given CSC amplifier: RIN, ROUT, Av, Ai , maximum input amplitude without distortion vin max , etc.

• To verify the small signal performance for a given CDC amplifier: RIN, ROUT, Av, Ai , maximum input amplitude without distortion vin max , etc.

• To establish the relationship between the voltage gain and the load

Figure # 1

1.- (HW) Analysis

1. Analyze the circuit shown in Figure # 1 (use nominal values) and find VGG, VG, VS, VD, and ID (assume VDD = 30 Volts DC, K = 40 mAmp/Volt , Vth = 1.73 V).

 
2. Assemble this circuit on SPICE and perform a bias point detail analysis. Show the calculated voltages and currents by appropriately placing IPROBEs and VIEWPOINTs on your schematic.

2.- Verification

1. Build and fully test the circuit shown in Figure #1. Measure  VG, VS, VD, and ID.

3.- (HW) Analysis

For the circuit in Figure # 1. With the values obtained for the bias currents and voltages:

1. Assuming that this circuit is operated in CSC (with shorting capacitor):

 
1. Find ROUT, RIN, Avo, Av (RL=ROUT) and Ai (RL=ROUT).
2. Also, find the maximum input voltage vin max that the amplifier can accept before the output distorts (loaded and unloaded).

 
2. Assuming that this circuit is operated in CDC (with shorting capacitor):

 
1. Find ROUT, RIN, Avo, Av (RL=ROUT) and Ai (RL=ROUT).
2. Also, find the maximum input voltage vin max that the amplifier can accept before the output distorts (loaded and unloaded).

4.- Verification

Build and fully test the circuit shown in Figure #1. By applying a sinusoidal signal such that the small signal approximation holds, measure:

1. For the CSC:

 
1. RIN (input impedance) and ROUT (output impedance) of the assembled circuit.
2. Voltage gain Av the assembled circuit for the unloaded case, and for RL equal to 2*ROUT, ROUT, ROUT /2, and ROUT /4.
3. Find the maximum input voltage that the amplifier can accept before the output distorts (loaded case RL = ROUT). Plot the output signal and the corresponding input.
4. Determine the phase relationship between the input and output voltages.
5. Compare the measured results to your analysis calculations.

 
2. For the CDC:

 
1. RIN (input impedance) and ROUT (output impedance) of the assembled circuit.
2. Voltage gain Av the assembled circuit for the unloaded case, and for RL equal to 2*ROUT, ROUT, ROUT /2, and ROUT /4.
3. Find the maximum input voltage that the amplifier can accept before the output distorts (loaded case RL = ROUT). Plot the output signal and the corresponding input.
4. Determine the phase relationship between the input and output voltages.
5. Compare the measured results to your analysis calculations.

5.- Conclusion

   a.Considering that these amplifiers are quite typical, what can you say about Rin, Rout, and the Av for the CSC and CDC  amplifiers.

   b.Based on your observation, what are the primary differences between BJT and MOSFET Amplifiers?

   c.Compare the measured results to your design calculations and specifications. Explain any and all differences!