EET2222 – Electronic Devices and Circuits

Lab 12 – Operational Amplifier Circuits

INVERTING OP-AMP CIRCUIT

1. Measure and record the values of the resistors RF and RI and from these values predict the expected value for the voltage gain in the circuit of Figure 1.

Figure 1

2. Set up the circuit using a 741 op amp in the mini DIP plastic package (don't forget the power supply connections).

3. Monitor input and output voltages with the oscilloscope and measure the values of the input and output voltages with the DMM to determine the measured value of voltage gain. Compare the results of the theoretical calculation and the experimental results. Use a frequency of 1 kHz and a sinusoidal input voltage of 0.5 Vrms. Sketch or print your input and output signals showing the phase relationship (label axis with units and calibration points).

4. Increase the amplitude of Vin until the output signal starts to clip. What is the maximum p-p amplitude for Vout?

NONINVERTING OP-AMP

5. Calculate the voltage gain for the circuit of figure 2. Set up the circuit and repeat part 3 using Vin = 0.25 Vrms.

Figure 2

6. Vary the frequency of Vin from 10 Hz to 100 kHz, measure Vin and Vout, and calculate the voltage gain and decibel voltage gain. Plot your gain information on semilog graph paper.

Your lab report is due at the end of the period. Please use the green engineering paper.