18-04-2014, 03:21 PM
h-PARAMETERS OF CE CONFIGURATION
AIM:
To calculate the H-parameters of transistor in CE configuration.
APPRATUS:
Transistor BC 107
Resistors 100 K Ώ 100 Ώ
Ammeter (0-200µA), (0-200mA)
Voltmeter (0-20V) - 2Nos
Regulated Power Supply (0-30V, 1A) - 2Nos
Breadboard
THEORY:
INPUT CHARACTERISTICS:
The two sets of characteristics are necessary to describe the behavior of the CE configuration one for input or base emitter circuit and other for the output or collector emitter circuit.
In input characteristics the emitter base junction forward biased by a very small voltage VBB where as collector base junction reverse biased by a very large voltage VCC. The input characteristics are a plot of input current IB Vs the input voltage VBE for a range of values of output voltage VCE . The following important points can be observed from these characteristics curves.
1. The characteristics resemble that of CE configuration.
2. Input resistance is high as IB increases less rapidly with VBE
3. The input resistance of the transistor is the ratio of change in base emitter voltage ΔVBE to change in base current ΔIB at constant collector emitter voltage ( VCE) i.e... Input resistance or input impedance hie = ΔVBE / ΔIB at VCE constant.
RESULT:
The H-Parameters for a transistor in CE configuration are calculated from the input and output characteristics.
1. Input Impedance hie =
2. Reverse Transfer Voltage Gain hre =
3. Forward Transfer Current Gain hfe =
4. Output conductance hoe =