Lab #4
Follow the instruction and procedures in the Student Manual, unless specified differently
in this note.
Reading:
p.82 – 99 in SM
p.61 – 79 in AE
Lab #4
4-1 Follow the instruction. Ignore the last sentence “You can even distinguish….” You
will find that is not the case. Don’t be surprised to see larger BC junction than BE.
4-2 Follow the instruction.
4-3 Follow the instruction. You will have to estimate two β values from Zin measurement
and Zout measurement (lens effect). Does it make sense?
4-4 Follow the instruction. Do you see (+)-side clipping is different from (-)-side one? In
answering the fine point, consider what would happen if Vb > Vc. Consider the basecollector junction as another p-n junction. The base will start to see collector
(meaning current will flow to collector).
4-5 Follow the instruction. You will measure β directly in this experiment. Identify the
region where you have almost constant β values.
4-6 Follow the instruction. You can use resistor box instead the 10K variable resistor.
Plot I vs R and identify the region of a good I-source. Estimate at what load
resistance you should observe current drop. Voltage compliance is the lowest
collector voltage where the transistor work as a good I-source?
4-7 Follow the instruction. Don’t forget to put your OSC in DC coupled mode to see the
quiescent point. Does it form a low pass filter or high pass filter? What R and C
form the filter? When you measure the output impedance, why do you have to use a
blocking capacitor? Use about 5 kOhm resistor to measure Zout.
4-8 Do this part. It is not optional.
4-9 Skip this part.