Basics of electronic ...

Exercise 1:

Design a voltage-transistor amplifier based on the BC547A transistor. Use the model:

.model bc547a NPN BF=400 NE=1.3 ISE=10.3F IKF=50M IS=10F VAF=80 ikr=12m BR=9.5 NC=2 VAR=10 RB=280 RE=1 RC=40 VJE=.48 tr=.3u tf=.5n cje=12p vje=.48 mje=.5 cjc=6p vjc=.7 isc=47p kf=2f

Project parameters:

- voltage gain \(k_u = - 10V/V\),

- input resistance \( r_{in} = 8 k\Omega\),

- output resistance \(r_{out} = 4k\Omega\),

- supply voltage \(U_{cc} = 12 V\).

Calculate \(R_1\), \(R_2\), \(R_C\) and \(R_E\) and \(U_{CC}\), \(U_B\), \(U_E\) and \(U_C\).

Simulate the designed amplifier and determine the DC voltages in the system \(U_{CC}\), \(U_B\), \(U_E\) and \(U_C\).

Measure the dependence of the output voltage as a function of the input voltage at the frequency f=1kHz by observing the input and output waveforms in the time simulation (transient analysis).

And then determine the dependence of the voltage gain modulus on the frequency using the ac simulation (Bode plot) from 1Hz to 100MHz.

Measure the input resistance of the amplifier using the technical method at the frequency of f=1kHz. To do this, add a variable resistor between the generator and the amplifier and vary its resistance to get half the peak-to-peak voltage at the output. Then the resistance will be equal to the input resistance of the amplifier.

Similarly, measure the output resistance of the amplifier using the technical method by adding a variable resistor at the output of the amplifier to ground. Adjust the resistance to get half the signal without the resistor. Compare the results with the video: