Laboratory Manual - King Fahd University of Petroleum and Minerals

You must have your SPICE output file with your hand calculations ready before
you come to the lab.
Part I:
EXPERIMENTAL WORK
1. Construct the circuit shown in Figure 1 and apply a small ac signal v sig with a
frequency in the midband (about 10kHz) and make sure by monitoring the
oscilloscope that the output voltage is not distorted. Measure the midband gain. Use
v sig that results in maximum undistorted output in the remaining steps.
Keep monitoring the input value during measurement to keep it fixed.
2. Decrease the input frequency gradually to determine f L
.
3. Go back with the frequency to 10kHz and increase it gradually to find f H
.
4. Remove Rs (short circuit) and measure the midband gain for the amplifier of Figure
1. Use the result of this step and step 1 to calculate the input resistance using the
formula: R in / (R in +R sig ) =(Gain with R sig )/(Gain without R sig )
5. Reconnect Rs and remove RL (open circuit) and measure the midband gain for the
amplifier of Figure 1. Use the result of this step and step 1 to calculate the output
resistance using the formula: R L / (R L +R out )=(Gain with R L )/(Gain without R L )
6. Now remove the resistor R F and capacitor C F and repeat steps 1 through 5.
7. Record your results in Table I.
8. Compare your hand calculations, SPICE simulations and experimental measurements.
9. Comment on your results.
Part II:
10. Connect the circuit of Figure 2. Apply sinusoidal signal of 10V (P-P), and frequency
1 KHz and monitor both the input and output signals using the oscilloscope.
11. Use the oscilloscope to display the transfer characteristics with output V o vertically
and input V i horizontally. Make sure to establish convenient axes near the lower left
corner of your oscilloscope screen. Note to observe the transfers characteristics use
the X-Y format, which you can find on the display setting of the oscilloscope.
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