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EXPERIMENT NO- 7

AIM:-

To draw the

(i) Drain characteristics

(ii) Transfer characteristicsOf N-channel Metal oide field effect transistor (MO!"ET)

APPARAT#! RE$#IRED :

E%eri&ental 'it

olt&eter -*olt +Nos

olt&eter -, +Nos

A&&eter -*&A +Nos

onnectin. /ire

irc0it Dia.ra&:

S

D

0 - 5 V D C

G

2 N 3 1 7

V G S

0 - 5 V o l t D C

I C

0 - 2 0 m A

1 k

0 - 1 2 V D C

1 k

0 - 2 0 V o l t D C

V D S

irc0it Dia.ra& of N hannel MO!"ET (De%letion &ode)

S

D

0 - 5 V D C

G

2 N 3 1 7

V G S

0 - 5 V o l t D C

I C

0 - 2 0 m A

1 k

0 - 1 2 V D C

1 k

0 - 2 0 V o l t D C

V D S

irc0it Dia.ra& of N hannel MO!"ET (E &ode)

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Theory

MO!"ET is a three ter&inal de1ice(drain2 so0rce2 .ate)si&ilar to 34T5 The difference

6etween the& is that the MO!"ET is a 1olta.e controlled de1ice 2whereas 34T is a c0rrent

controlled de1ice5 "i.0re -+: The Metal Oide "ield Effect Transistor(NTE 8+*)Drain

haracteristics: /hereas for 34T the relationshi% 6etween an o0t%0t %ara&eter2 Ic2 andan in%0t %ara&eter2 I62 is .i1en 69 a constant 2 the relationshi% in MO!"ET 6etween an

o0t%0t %ara&eter 2Id and an in%0t %ara&eter2 .s is &ore co&%le5 In the sat0ration

re.ion2 there eists a s;0are-law transfer relationshi%5

Transcond0ctance haracteristics: In the transfer characteristics of a two %ort

networ

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PROED#RE::

+5 onnect the circ0it as shown in fi.5

*5 !et =!> olt5 'ee% -,olt 1aria6le %ower s0%%l9 at anticloc< wise

direction for &a olt5

85 Now increase the D!in ste% sa9 +1olt startin. fro& ?ero and o6ser1ethe corres%ondin. Drain 0rrent (ID) in &ili a&&eter5

@5 Re%eat ste% * for different =!1al0e sa9 -5,2-+2 -+5,2 -*

,5 Plot the .ra%h 6etween D!1s ID

To draw the transfer characteristics

The t9%ical Drain characteristics are shown in fi.5 +

TRANSFER CHARACTERISTICS:

ID( &A)

D!> onstant

"i.5 + =!(1)

In order to draw the a6o1e characteristics %erfor& followin. ste%s:

+5 The circ0it will 6e sa&e for o6tain the transfer characteristics5

*5 !et the D!> 85 69 1ar9in. the -+*olt 1aria6le %ower s0%%l95

85 Now increases the =!in ste% sa9 -5,olt startin. fro& ?ero and

o6ser1e the corres%ondin. drain c0rrent ID0ntil ID6eco&e ?ero5

@5 Re%eat ste% * for different 1al0e of D!5

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,5 Plot the .ra%h 6etween =!1s ID5

O3!ERATION TA3E "OR DRAIN BARATERI!TI!

=!> olt =!> 5,olt =! >-+olt =!> -*olt

D!(olt) ID(&A) D!(olt ID(&A) D!(olt ID(&A) D!(olt ID(&A)

5,

+

+5,

**5,

8

85,

@

@5,

,

7

C

O3!ERATION TA3E "OR TRAN!"ER BARATERI!TI!

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D!> 8olt D!> ,olt

=!(olt) ID(&A) =!(olt) ID(&A

-5, -5,-+ -+

-+5, -+5,

-* -*

-*5, -*5,

-8 -8

-85, -85,

-@ -@

-, -,

alc0lation

The various parameters of a MOSFET are:

1.A DRAIN RE!I!TANE2 rd: It is the resistance between drainand source terminals

when MOSFET is in the Pinchoff re!ion.

rd " chan!e in #$S% chan!e in I$.

&.TRAN!OND#TANE (.&):Slope of transfer characteristic.

!m "chan!e in I$% chan!e in #'S

(.AMPI"IATION "ATOR: It is !iven b)

*.F. " +han!e in #$S% +han!e in #'S.

,5D DRAIN RE!I!TANE2 Rds: It is !iven b) -

$S" #$S%I$S

Res0lt

.A DRAIN RE!I!TANE >---------------------

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TRAN!OND#TANE (.&) >---------------------

AMPI"IATION "ATOR >------------------------

D DRAIN RE!I!TANE2 R >------------------------

PREA#TION!:-

+5 Do not eceed the ID drain c0rrent +&A5

*5 Ta