Prelims Lecture 2

Load-line plots all the possible combinations of the diode current ID and voltage VD for a given circuit

Q-point the point where the load line and the characteristic curve intersect

Determine (a) VDQ and IDQ (b) VR

Si

10 V E

R 1k

ID 10

ID(mA)

VD(V) 0.8

Answer

10V

IDQ = 9.25 mA

VDQ = 0.78 V

Q point

Repeat using the simplified equivalent

circuit.

Repeat using the ideal diode equivalent

circuit.

Answers

10V

IDQ = 9.25 mA

VDQ = 0.78 V

Q point Q point

Answers

10V

IDQ = 10 mA

VDQ = 0.78 V

Q point

VDQ = 0V

Forward Bias

Reverse Bias

Determine (a) VD (b) ID (c) VR

Si

8 V E

R 2.2k

ID

Determine (a) VD (b) ID (c) VR

Si

8 V E

R 2.2k

ID

Determine (a) VD (b) ID (c) VR

Si

0.5 V E

R 1.2 k

ID

Determine VO and ID.

12 V Vo

Si red R

680

Color Constructi

on

Typical

Voltage

(V)

Amber AlInGaP 2.1

Blue GaN 5.0

Green GaP 2.2

Orange GaAsP 2.0

Red GaAsP 1.8

White GaN 4.1

Yellow AlinGaP 2.1

Determine ID, VD2 and VO.

Determine I, V1, V2 and VO.

I

+ V1 -

+

V2

-

Determine I1, ID1, ID2 and VO

Determine the current I in the circuit.

R

2.2 k

E1=20V E2=4V

I

Si

Si

D1

D2

Determine the voltage VO. 12 V

Vo

R

2.2 k

Si Ge

Determine I1, I2 and ID2.

R1

3.3 k

R2

5.6 k

I1

I2 ID2

E = 20V

Si

Si

D1

D2

1.(a) Using the characteristics shown on the

next slide. Determine ID, VD, and VR for the

given circuit. (b) repeat part a using the

approximate model (c) repeat part a using

the ideal diode model.

2. Determine Vo and ID.

3. Determine VO and ID.

4. Determine VO1, VO2 and I.

Prepare for a long quiz next meeting

Read and study your reference book and

dont just rely on the power point presentation.