The University of Tennessee s3

ECE 335 PROJECT II

Design, build, test and simulate a transistor voltage amplifier according to the specifications given below.

SPECIFICATIONS: (a) The small signal voltage gain (vo/vs) must be -10  10% at a signal frequency of 10 kHz (midband) with an output signal level of 5 V peak-peak. Follow the schematic shown in figure 1.

(b) The power supply voltage is to be +15 V DC and maximum quiescent power supply current is 5 mA. The output signal as observed on the oscilloscope must show no evidence of severe distortion (clipping) when the output signal level across 2 k load resistor is 5 V peak-peak. Obtain the oscillographs to submit in the report.

(c) Characterize the BJT to obtain SPICE parameters BF, VA, and IS for your transistor.

(d) Perform SPICE simulation to obtain bias voltages and currents and run transient simulation to obtain output voltage waveform using a sinusoidal input waveform. Verify the midband voltage gain when the output signal is 5V peak-peak at 10 kHz . Obtain the maximum output voltage swing without clipping.

(e) Take gain magnitude measurements at three frequencies: 1) somewhere in the middle of the band, 2) at the lower 3 dB point (-3dB with respect to your first measurement), and 3) at the upper 3dB point.

(f)The report should be submitted along with the circuit. Experimental measurements should be supported by design calculations. SPICE output must be included in the report (either attached as an appendix or pasted in the main body of the report). A summary of SPICE results must be included in the report. The report should also include a complete circuit diagram of amplifier clearly showing all component values.

(g) The report format should be in IEEE Transaction style. The page limit is 6 pages. The grading of the report will be based on the technical content as well as the writing and organization of the report.

Example amplifier circuit Project II

STUDENT'S NAME ______

T.A.'s NAME ______DATE ______

CHECK-OFF PROCEDURE:

1. Apply a 0.5 V peak-peak, 10 kHz sine wave to the amplifier input and measure the voltage gain with the power supply at + 15 V DC.

Gain = ______

2. Increase the input signal amplitude and measure the maximum symmetrical signal swing at the output without noticeable clipping or distortion using a power supply of + 15 V DC.

Maximum Symmetrical Output Swing (peak-peak) = ______

3. Remove the input signal and measure the current drawn by the circuit from the +15 VDC power supply.

Current = ______

4. Does the amplifier use at least one 2N3904 BJT and does it by design have 10 k in series with the source and 2 k in series with the load ? Also verify how many capacitors are used in the amplifier circuit.