Analog electronics Experiment 9 aimTo study and plot the characteristics of JFET in its various configurations.

 Note remember page numbers

Apparatus:

Bread board, variable and fixed D.C. Sources, JFET, resistances, multimeters, connecting wires.

OR

FET Characteristics trainer kit with connecting leads and power supply.

Theory: An FET is a three terminal semiconductor device in which current conduction is by 

one type of carries & is controlled by the effect of electric field. There are two types of FET 

namely JFET & MOSFET. Again, a JFET can either have N-channel or P-channel. A N-channel 

JFET has a N-type semiconductor bar, the two ends of which make the Drain & source terminal. 

On the two sides of this bar, P-N junction is made. This P region makes gate. Usually, these two 

gates are connected Together to form a single gate .The gate is given a –ve bias w.r.t. source. 

The Drain is given +ve potential w.r.t. source

Theory: An FET is a three terminal semiconductor device in which current conduction is by 

one type of carries & is controlled by the effect of electric field. There are two types of FET 

namely JFET & MOSFET. Again, a JFET can either have N-channel or P-channel. A N-channel 

JFET has a N-type semiconductor bar, the two ends of which make the Drain & source terminal. 

On the two sides of this bar, P-N junction is made. This P region makes gate. Usually, these two 

gates are connected Together to form a single gate .The gate is given a –ve bias w.r.t. source. 

The Drain is given +ve potential w.r.t. source

Procedure:

Common Source Configuration

Input characteristics:

(a)Connect the circuit as per the circuit diagram.

(b)Keep drain-source voltage constant.

(c)Vary gate-source voltage in steps and note down drain current.

(d) Readings are tabulated and graph is drawn.

Output characteristics:

(a)Connect the circuit as per the circuit diagram.

(b) Keep gate-source voltage constant.

(c)Vary drain-source voltage in steps and note down drain current.

(d) Readings are tabulated and graph is drawn

Common Drain Configuration

Input characteristics:

(a)Connect the circuit as per the circuit diagram.

(b)Keep drain-source voltage constant.

(c)Vary gate-drain voltage in steps and note down drain current.

(d) Readings are tabulated and graph is drawn.

Output characteristics:

(a)Connect the circuit as per the circuit diagram.

(b)Keep gate-drain voltage constant.

(c)Vary drain-source voltage in steps and note down drain current.

(d) Readings are tabulated and graph is drawn.

Conclusion: Input and output characteristics of JFET are obtained

Precautions:

(a) Always connect the voltmeter in parallel & ammeter in series as shown in fig.

(b) Connection should be proper & tight.

(c) Switch ‘ON’ the supply after completing the circuit.

(d) DC supply should be increased slowly in steps

(e) Reading of voltmeter & Ammeter should be accurate.