MOSFET (Metal Oxide Semiconductor Field Effect Transistor)

In this lab student will be familiar with a Voltage Controlled Current Source (VCCS). A n-channel

MOSFET (ZVN2210A) has three terminal that are called source (S), drain (D), and gate (G).

Gate control the drain current.

Figure 1: A MOSFET Circuit

If the gate voltage goes up, drain current goes up.

A 100 ohms resistor in the circuit will limit the

amount of current flowing through the MOSFET.

Also a digital ammeter is connected series with

the resistor in order to measure the  drain current.

A 5 volts Dc power supply is used.

Figure 2: A Dependent Current Source Controlled with Voltage

voltage applied (V)	current measured (mA)
0	0
0.4	0
0.8	0
1.2	0
1.6	0
2	1.8
2.1	5.1
2.2	11
2.3	20.5
2.4	33
2.5	44.9
2.6	47.3
2.7	47.9
3.1	48.7
3.5	49
3.9	49.1
4.3	49.2
4.7	49.2
5	49.3

According to the current-voltage graph of MOSFET, the threshold voltage 1.6 volts.

The slope of the linear part of current-voltage cure is inverse of gain.

Two points of (44.9 mA , 2.5 v) and (1.8 mA , 2.0v) are used for this reason.

So (1/g) = [(44.9 - 1.8)*E-3] / (2.5 - 2 ) , g = 11.6 ohms

voltage applied (V)

current measured (mA)

0

0

0.4

0

0.8

0

1.2

0

1.6

0

2

1.8

2.1

5.1

2.2

11

2.3

20.5

2.4

33

2.5

44.9

2.6

47.3

2.7

47.9

3.1

48.7

3.5

49

3.9

49.1

4.3

49.2

4.7

49.2

5

49.3