EE 321L Analog Electronics Laboratory Fall 2010Lab 1Amplifiers, input/output resistance, cascades, and frequency responsePre-Lab1. Design the amplifier in question 1.2. Design the amplifiers in question 5, derive an expression for Avoof the cascade, andcompute the expected value.3. Design the amplifiers in question 6.Input and Output Resistance1. Using a LM 741 op-amp, build an inverting voltage amplifier with a gain of approx-imately 100, and input and output resistances of 1 kΩ (Hint: the circuit is a regularinverting amplifier followed by a series resistor). Measure the resistors and compute a nactual theoretical gain, Avo.2. Attach the function generator directly to the input, and the output directly to a voltage-meter or the oscilloscope input. What are the source and load resistances? Use the DCoffset of the function generator to provide an input signal. Measure and plot the outputvoltage for several values of the input voltage. It should be a linear relationship witha slope of 100. What is the output for zero input? A non-zero output for zero input isrelated to a DC imperfection in the op-amp which we will discuss in class.3. Sketch and carry out an experiment to measure the input and output resistances ofthe amplifier using DC signals. You can use the function generator’s DC offset withseveral suitable series resistors at the input. On the output, attach several suitable loadresistors. Compare the results to the actual resistor values.Frequency Response4. Next, measure the frequency response o f the amplifier. Use a small-amplitude sinusoidalinput, gradually increasing the frequency until the gain has dropped significantly. Plotthe gain and phase difference between input and output as a function of frequency.NOTE: At high frequency you must use a small amplitude input signal. If you noticeany distortion of the output causing it to look triangular, reduce the input signalamplitude.1EE 321L Analog Electronics Laboratory Fall 2010Amplifier cascades5. Build a two-stage amplifier cascade consisting of two inverting amplifiers, each witha gain of 10 and each with input and output resistances of 1 kΩ. Measure Avoof thecascade.6. Modify the gains of the individual amplifiers (keeping them identical) to produce anAvoof approximately 100. Measure the new gain.7. Measure the frequency response of this cascade. Compare the results with the single-stage amplifier and
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