# 计算机与电气工程代写 | ECE-171 Computer and Electrical Engineering

1. Discuss the idea of parametric models from a system level perspective and proceed to develop a 2-port
model for the small-signal diode experiment using h-parameters. Explain what gets abstracted with this
model. Are there any restrictions using this particular model?

2. Suppose two pn diodes are connected in parallel, and regardless of the voltage across them have
precisely the same current flowing in each branch. Exactly what conditions must occur for this to
happen (saying they’re “matched” is not sufficient)? Do these same conditions apply if the diodes are
now connected in series, i.e. where the voltages accross each are now precisely the same? Sketch both

3. The amplifier circuit shown has three gains associated with it, power, voltage and current. Determine
all three gains at 1kHz and 10kHz and express them in dB and scalar units. Draw an equivalent circuit
with the op-amp replaced by a suitable engineering model.

The op-amp’s has the following specifications:

input impedance is 10Meg. Its output resistance is 100 Ohms

4. Using the constant voltage drop diode model, accurately sketch the transfer characteristic for
2 V
vs.
1 V

when
2 V
is open-circuited as shown, and when it is connected to a 100k load resistance. What kind of
circuit is this?

5. An audio engineer is interested in using one or more LM741 op-amps in an amplifier that needs 50 dB
of minimal voltage gain from 30 Hz to 15 kHz. Available supply rails are +/- 15 Volts. Design a circuit
using these devices that meets the minimum following specifications:
 Gain variation cannot exceed 3 dB over the wanted frequency range.
 The maximum undistorted output voltage,
3.0  op
vV
.

Since there are many datasheets available for this op-amp, only use the one provided on our website
associated with this exam. E-mail: itcsdx@outlook.com  微信:itcsdx 