ECE 2212 PROBLEM SET 7

S. G. Burns

Due: 22 October 2003

  1. Text 4.2 and Text 4.3 as a combination. Tabulate your results and for each case, draw a diagram of the transistor with the bias voltages carefully labeled with the correct sign. When you tabulate your results, list whether each of the two junctions is either reverse or forward biased.

 

2.     Text 4.8.   You can and should ignore the leakage current. Partial answers include IC = 8.61 mA and for Part (b), you will show saturation with    IC = 5.25 mA.  Besides the analytical solution, verify your results with a SPICE simulation.  Justify  that the SPICE default npn has specifications  close to the specifications listed in the problem. To obtain this Q-Point information, look at the output file generated with the .OP command (which may or may not be a default operation in your version of SPICE).

 

3.     Text 4.14  Besides the analytical solution, verify the results using SPICE.  Use the sample programs discussed and demonstrated in Friday’s class for guidance.  In reference to using Figures 4.15 and 4.17, for both the analytical and SPICE, use the default npn BJT model but modified  for BETA = 150.  Assume VBE(on) = 0.7 volts for the analytical solution.

4.   Text 4.19 NPN Q-Point Analysis.    Label your voltages and currents carefully on the circuit diagram.  In addition, sketch and label a small-signal model for this circuit using the hybrid-pi BJT device model.  Model values must be computed.

 

5.   Text 4.20 PNP Q-Point Analysis.    Label your voltages and currents carefully on the circuit diagram.  In addition, sketch and label a small-signal model for this circuit using the hybrid-pi BJT device model.  Model values must be computed.

 

6.   Text 4.34    Recognize that the current through the collector resistor consist of IB + IC.  Partial answers include IBQ = 35 mA, ICQ = 2.62 mA.  The inclusion of the 47 kW resistor provides good practice in setting up and solving node equations.