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Unformatted text preview: Experiment 8: Multi-stage Amplifiers 1 Objective A single transistor amplifier stage usually does not provide enough gain and/or the proper I/O impedances for the desired application. To remedy this, we can cascade several amplifier stages to form a multi-stage amplifier that has the appropriate properties. In this lab, we begin with an evaluation of the cascode amplifier before moving on to the multi-stage amplifier. Note that multi-stage amplifiers can be made from several different combinations of amplifiers; however, we only utilized the common emitter and common collector amplifier for this particular experiment. 2 Materials The items listed in table 1 will be needed. Note: Be sure to answer the questions on the report as you proceed through this lab. The report questions are labeled according to the sections in the experiment. CAUTION: FOR THIS EXPERIMENT, THE TRANSISTORS CAN BECOME EXTREMELY HOT!!! Component Quantity 2N4401 NPN BJT 4 2N4403 PNP BJT 2 51 kΩ resistor 2 20 kΩ resistor 1 100 Ω resistor 2 51 Ω resistor 1 10 kΩ potentiometer 1 10 μ F capacitor 2 Table 1: Components used in this lab 3 Procedure 3.1 Cascode Amplifier 1. Construct the cascode amplifier ( Q 1 and Q 2 ) and the current mirror ( Q 3 and Q 4 ) as shown in Figure 1(a). Use two 51 kΩ resistors in parallel to make the 25 . 5 kΩ resistance for R REF and use a 51 Ω resistor for R S . Also, set V BIAS 2 to 1 . 5 V. 2. Use the function generator to create v IN , a 1 kHz, 20 mV pp sine wave with a DC offset between 580 mV to 650 mV; you may have to adjust the offset to get a clean output signal....
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- Spring '08
- Direct Current, Resistor, Input impedance, Output impedance, common collector amplifier