1. EN1072 Laboratory
Answers:
Bipolar Junction Transistor
Experimental Aims
To meaningfully interpret the DC-IV characteristics of the Bipolar Junction
To provide a specification of the maximum current IMAX of the Bipolar Junction Transistor
needed for the specific design.
To ensure the effective utilization of the DC-IV data in the effective design of the of the
power amplifier to effectively maximize the potential.
Objectives Of The Experiment
To understand the general BJT operation
To understand the general DC-IV characteristics of the BJT and be able identify the key
abilities in the characteristics for the PV system design.
To effectively understand the variability of the devise parameters of both the
semiconductor and the passive parameters and the general effects of the stated variability
on the general design of the system.
To recognize the potential pitfalls and optimize the circuit parameters
Common Emitter Amplifier Topology
The amplifier to be designed has the following design specification
100mW powers supply supplied into the load at the frequency of the signal.
620Ohms load resistor
A frequency signal of 465KHz
The signal drive is 0.707Vrms (2Vpp )
A 9V power supply
Class A operation with a linear load value 630Ohms.
Experimental Theory
The Bipolar junction transistor can be described as a controlled current source; the input
current of the transistor controls the output transistor current. For the BJT, the base emitter
current is the input (Liu et al., 2019). A design where the output current is controlled by the
input and this is achievable through the effective use of an amplifier. The design aspect is
where the biasing becomes quite essential as it plays an effective role in ensuring that ta
2. desired out is effectively achieved in the design. The transistor circuit is thus operated in a
predetermined operation point. BC107 is utilized in the experimental investigation. The
resistors R1 and R2 are utilized in the setting of the biasing currents desired for the
operation of the circuit. RE is used in the setting of the bias potential for the VCEQ.
Experimental Procedure
The BJT was effectively simulated through the us eof the circuit configuration, The collector
current verses the collector voltage was effectively plotted in order to effectively obtain the
output characteristics.
The collector current iCe was then effective plotted against the base current Ibe in order to
obtain the transfer characteristics of the circuit.
Since a design criterion is that the PA be made using a 9 V battery/power supply we can use
this to Since the design considered was that of the power amplifier, a 9V power supply was
used considering no distortion made on the current and the respective voltages. Note, the
class A operation considers that all the input signal is allowed in effectively conducting
current at the output. This implies that the output signal is neither squashed nor clipped.
The respective regions of the output have been effectively defined.
Data Analysis And Discussion
Pload = (9v)^2 /
The green line given in the diagrammatic representation shows the 9V , which is where the
465KHz waveform undergoes effective oscillation. The Vk and VMAX are equidistant from
9V supply and this is very effective in terms of setting out the maximum range of the AC
sinusoidal output.
Experimental Analysis
Pload =/ 620= 130.65mW
Vpeak-Peak =16.1V
Vpeak = 8V
Vrms = Vp/
Vrms = 8/
Vrms = 5.66V
3. Maximum output power = /Zload
We utilized the Rms voltage in conducting the manipulation
=/620
=51.61mW
The peak to peak current is also effectively calculated using the following formulation
Ipeak to peak= Vpeak-peak/ Zload
= 8/620=12.9mA
=0.0129A, This is the value of the peak to peak current as obtained from the experimental
investigation.
The experiment was also effectively used in obtaining the values of the operation
parameters for the experimental investigation.
The value of ICEQ utilized for the experimental investigation is obtained using the following
formulation
=12.9mA/2= 6.45mA
The value of the current gain has also been effectively used in obtain the blue of IBEQ for the
specific circuitry utilized for the experimental investigation.
The beta value is obtained using the following formulation
From the data sheet the average current gain is 110
IBEQ= 6.45mA/100=0.00645mA
The following values have been effectively calculated in respect to the respective values of
the Common emitter collector and the values obtained from the data sheet which has been
used for the experimental investigation. The Kirchhoff law play an instrumental law in
drawing an effective analysis of the experimental investigation.
Discussion
In the experiment, BJT biasing circuit was effectively studied and the respective operation
4. points effectively calculated. The unique characteristics of the BJT come from the BJT
interaction between two junctions the emitter and the collector. The graphical
representation has been utilized in illustrating how the current varies in respect to the
variation of the voltage. One of the other critical aims of the experiment was to effectively
obtain the current gain. The experimental experiment was thus very effective in obtaining
the gain. The input current is denoted as the ib and the output current as ic, then gain was
thus effectively obtained through the consideration of the two current values (Liu et al.,
2019). The formulation for the current gain is obtained as ic/ib. The current gain value is
non-dependent on the value of the ib since it increases on the same way as the value of the
output current ic. The pload values were also effectively calculated through the utilization of
the formulation engaged in the analysis section of the experimental report.
Conclusion
By effectively utilizing the ohms law the values of the currents voltages and the diode
resistors were effectively measured. The transistor was a very effective component in
achieving the current gain desired for the circuitry. The collector current entering the BJT
transistor is very effective in terms of effectively deriving the differential amplifier which is
necessary for the general operation of the circuit. The experimental investigation was thus
very effective in terms of obtaining the current gain and also obtaining then DC-1V
characteristics of the BJT. The graphical representation was effectively utilized in deriving
the experimental analysis and investigation.
References
Liu, L., Xu, N., Zhang, Y., Zhao, P., Chen, H., & Deng, S. (2019). Van der Waals Bipolar Junction
Transistor Using Vertically Stacked Two?Dimensional Atomic Crystals. Advanced Functional
Materials, 29(17), 1807893.
