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EXPERIMENT NO. 4 Transistor Common-Emitter Configuration Characteristics

Group 5:Dela Cruz, Mark LouieMendoza, Allen RodneySampayan, GlennTambaoan, Christian Alan

DATA:

A.) Input characteristics:

VBB VCE = 1 V V CE = 2 V V CE = 4 V

VBE (V) I B (A) VBE (V) I B (A) VBE (V) I B (A)0 V 2.007x10 -11 V -0.0002007 A 2.229x10 -11 V -0.0002288 A 2.852X10 -11 V -0.0002852 A 6 V 0.886 V 51139 A 0.887 V 51132 A 0.888 V 51118 A

12 V 0.978 V 110222 A 0.97844 V 110216 A 0.98 V 110202 A18 V 1.06 V 169404 A 1.06 V 169397 A 1.062 V 169384 A24 V 1.138 V 228624 A 1.138 V 228617 A 1.14 V 228605 A

30 V 1.214 V 287864 A 1.124 V 287858 A 1.215 V 287845 AB.) Output characteristics:

S. No.IB = 50 A I B = 75 A I B = 100 A

VCE (V) I C (mA) V CE (V) I C (mA) V CE (V) I C (mA)0 V -0.003314 V 0.003315 mA 0.000003586 V 0.003586 mA -0.000003749 V 0.003749 mA6 V 0.08142 V 5.919 mA 0.064 V 5.936 mA 0.055 V 5.945 mA

12 V 0.141 V 11.86 mA 0.101 V 11.899 mA 0.085 V 11.915 mA18 V 3.049 V 14.951 mA 0.148 V 17.852 mA 0.115 V 17.885 mA24 V 8.082 V 15.918 mA 2.365 V 21.635 mA 0.158 V 23.842 mA30 V 13.115 V 16.885 mA 7.05 V 22.95 mA 2.082 V 27.918 mA

GRAPH:

A.) Input characteristics:

-0.0002852

51118

110202

169384

228605

287845

-50000

0

50000

100000

150000

200000

250000

300000

350000

0.00E+00 2.00E-01 4.00E-01 6.00E-01 8.00E-01 1.00E+00 1.20E+00 1.40E+00

1V 2V 3V

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B.) Output characteristics:

RESULT: The input and output characteristics of transistor connected in CE configuration have been observedand the of the transistor is calculated as _____ and its input and output Resistances are ______ and

________.

VIVA QUESTIONS:

1.) What is the range of for the transistor? The value of ranges from 50 -400.

2.) What are the input and output impedances of CE configuration? The input impedance would be higher and output impedance would be lower in a CE

configuration.

3.) Identify various regions in the output characteristics. Cut-off region

Saturation region

4.) What is the relation between and ? The DC Current Gain of the device is Beta, ( ). Also, Alpha ( ), the current gain of the

transistor from the Collector terminal to the Emitter terminal and is a function of thetransistor itself. As the emitter current is the sum of a very small base current plus avery large collector current, the value of alpha , is very close to unity. While Betareveals the magnitude of one current to the other.

5.) Define current gain in CE configuration. The common-emitter configuration is an inverting amplifier circuit, the circuit is

sometimes called as beta. Its current gained is obtained from the ratio of base and thecollector circuit elements.

6.) Why CE configuration preferred for amplification? Common-emitter configuration is preferred as amplification because of its capability to

produce the highest current and power among the three configurations.

7.) What is the phase relation between input and output?

0.003749

5.945

11.915

17.885

23.842

27.918

0

5

10

15

20

25

30

-2 0 2 4 6 8 10 12 14

1V 2V 3V

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The phase relation between the input and output is inversely proportional to eachother. Because as the voltage input increases the voltage output decreases.

8.) Draw diagram of CE configuration for PNP transistor.

9.) What is the power gain of CE configuration? The power gain for the common-emitter configuration is much higher than of the

remaining two configurations.10.) What are the applications of CE configuration?

The common-emitter configuration is mostly used as a switch, it amplifies voltage andcurrent. Gain is the factor by which amplification increases the voltage or current. Ithas a low input impedance and outputs high impedance, high voltage gain and currentgain.