Download ECET 2310 Laboratory Exercise 7: Op-Amp Characteristics and Circuit Analysis and more Lab Reports Electronics in PDF only on Docsity! ECET 2310 (Electronics II) Laboratory Exercise 7 (Revised 5/30/08) Basic Op-Amp Characteristics Prelab: 1. Determine the following µA741C specifications from the datasheet in your text: (a.) Input Offset Voltage, (VIO): ________ (typical) ________ (maximum) (b.) Input Bias Current, (IB): ________ (typical) ________ (maximum) (c.) Input Offset Current, (IIO): ________ (typical) ________ (maximum) (d.) Unity-gain frequency, f2(unity): ________ (typical) [determine from the typical voltage follower risetime] (e.) Slew Rate: _________ (typical) 2. Utilizing your results from Prelab part 1 (d.), determine the closed loop bandwidth when the circuit shown in Figure E is connected with the following values of RF: (a.) Closed loop bandwidth (when RF = 47 kΩ), f2(gain2): _________ (b.) Closed loop bandwidth (when RF = 100 kΩ), f2(gain3): _________ 3. Utilizing your results from Prelab part 1 (e.), determine the highest operating frequency at which a µA741C op-amp could be operated without developing output waveform distortion due to slew rate limitations. Assume the output waveform is a 10 Vpp sinusoidal waveform. fSR = _________ 4. Utilizing your results from Prelab part 1 (e.), consider the circuit of Figure E when RF = 10 kΩ and the op-amp is a µA741C. If vin is a 5 Vpp, 5 kHz squarewave, accurately sketch and label the predicted output waveform, vo, for two periods. 2 Procedure: 1. Construct the circuit of Figure A. Accurately measure and record the dc value of VO1 with the DVM. 2. Construct the circuit of Figure B. Accurately measure and record the dc value of VO2 with the DVM. 3. Construct the circuit of Figure C. Accurately measure and record the dc value of VO3 with the DVM. 4. Utilizing your measured results of VO1, VO2, and VO3 determine: VIO = ___________ IB+ = ___________ IB- = ___________ IB = ___________ IIO = ___________ 5. Construct the circuit of Figure D. Set vin(t) = 0.05 sin (1000πt) V. Monitor vin and vo on the oscilloscope. Increase the frequency of vin (while maintaining the amplitude of vin) until the output voltage, vo, decreases in amplitude by 3 dB (i.e. 70.7 % of its amplitude at 500 Hz). Record this frequency as f2(unity-meas). Note that f2(unity-meas.) is the practical value of your op-amp’s unity gain frequency or gain-bandwidth product. 6. Construct the circuit of Figure E and set RF = 47 kΩ. Set vin(t) = 0.05 sin (1000πt) V. Monitor vin and vo on the oscilloscope. Increase the frequency of vin (while maintaining the amplitude of vin) until the output voltage, vo, decreases in amplitude by 3 dB (i.e. 70.7 % of its amplitude at 500 Hz). Record this frequency as f2(gain2-meas.). 7. Modify the circuit of Figure E by changing RF to 100 kΩ. Set vin(t) = 0.05 sin (1000πt) V and repeat Procedure 6 with your modified circuit. Record the new frequency as f2(gain3-meas.). 8. Modify the circuit of Figure E by changing RF to 10 kΩ. Set vin to a 5 Vpp, 5 kHz squarewave. Accurately sketch and label the output waveform, vo, for two periods. Determine the slew rate from the slope of the output waveform. 9. Continue to utilize the circuit of Figure E with RF = 10 kΩ, except now set vin to a 1 kHz sinusoidal waveform. Adjust the amplitude of vin until the output waveform, vo, is exactly 10 Vpp. Increase the frequency of vin (while maintaining the amplitude of vin) until you observe visible distortion on the output waveform, vo. Record the lowest frequency at which you notice distortion. Identify this frequency as fSR(meas.). Observe how the output waveform, vo, changes shape when the frequency of the input voltage, vin, is increased beyond fSR(meas.). 10. Compare the prelab results with the associated measured results. List the possible sources of error. (revised 5/30/08 WRH)
