=========================preview======================
(ELEC102)test2_pasto.pdf
Back to ELEC102 Login to download
======================================================
3

(12)

(12)

3(a)



Text Box: (a) Given VA = 6.7V, VB = 1V. If S is closed, find I1 and I2. Assume D1 and D2 are offset diodes with VF = 0.7V.


Text Box: I1 = 6mA
Text Box: I2 = 0mA

3

(12)

(12)

3(b)

V2

-0.6V +

2.65mA

1V

1k.

V1





Text Box: 3. (b) In the ideal op amp circuit, the diode equation is
Text Box: Find I if V2 = V1 + 0.6V. (12)


4

-9V

D

(8)

(11)

(b)

-9V

D



Text Box: In the ideal diode circuit, sketch Vo(t) .(a) If X = C.(b) If X = R . (19)

Text Box: VO = Vi + Vc = Vi + 3V






5

VZO = 10V

rZ = 5.

(7)

(a)

(b)

(6)

(17)

(4)

0V



Text Box: Model at breakdown



Text Box: V1 = 10V diode is not breakdown and is an off diode (open)





(4)

(10)

4k.

0V


Text Box: V1= 25V Zener is breakdown




6

(16)

e

(10)

1. EBJunction is a forward bias (on) diodeand BC is reverse bias (off) diode
2. E is very heavily doped(N +for NPN). E has many electrons,
3. B is very thin. So most electronsinjected from E (to B) are attracted to C and

(a)

Text Box: Draw the cross sectional structure of a NPN BJT transistor operated in the amplifier mode, describe the movement of





7

(8)

RC = 1k.

RB = 1k.

(8)

(16)

10V

10V


Text Box: Sketch the small signal (AC) equivalent circuit of the BJT amplifier and find the voltage gain Av ( = Vout / Vin







8

(24)

10V

1k.

10V

1k.




Text Box: Find IC / IB . Show clearly your reasons. For the BJT, given VBE(ON) = 0.7V, . = 100, VCESAT = 0.2V. (24)








9


Text Box: Given the BJT circuit below and the IC -VCE curve of the BJT. VCEQ = 5V. (a) Draw the load line VCE = V1 .V ICR1



Draw load line,

(30)

(a)

(5)

(5)

(4)

VCE2 = 6V

Vin1 = 0.80V
IB1= 0.10mA

Vin2 = 0.76V
IB2 = 0.06mA

(8)






Text Box: VO (t) V


(15)

ID

IS

source usually shorted to body

Metallic film

IG= 0
ID= IS

An NMOSFET consists of a metal gateinsulated from a p-type semiconductorsubstrate (or body) by an insulating layer of silicon dioxide. On either side of the gate there are n type regions forming the drain and source.

(11)

10

(4)

(a)

(b)




Text Box: (a) Name two advantages of MOSFET. (b) Draw the cross sectional diagram for an enhancement NMOSFET and describe v


(22)

11

(7)




(15)

(8)

(4)

12

(3)



Text Box: Find K and RD.Given VT = 1V .

Text Box: VGS = 5V, VDS = 2V , MOS is Triode.
Text Box: Since VDS < VGS - VT
Text Box: VGS > VT


Text Box: Find K and RD . Show clearly the reasons for your answers. (15)Given that VT = 1V . At triode region


Gain Bandwidth Product (GBP)

13

(5)

(a)

(5)



Text Box: Gain of op amp circuit x bandwidth of op amp circuit = constant