Download Assignment 4

EE311 / Spring 2007
Homework # 4
1. Determine the output voltage vout and current iout for the circuit shown below.
7K
98 K
V-
10 K
+
V+ +
0.5sint
iout
20 K
AC
vout
2K
_
…
2. In the diode circuits (a) and (b) below, V= 5V and R=10 K. The diodes have an offset
voltage of VF= 0.7 V but with negligible resistance. Find the output voltages at C for each
of the following cases:
(i)
A=B=4V
(ii)
A = 4 V, B = 0 V
(iii)
A = 0 V, B = 4 V
(iv)
A =B=0V
+V
R
Vout
Vout
A
A
B
(a)
B
R
(b)
3. Calculate the following quantities for an abrupt silicon p-n junction diode with crosssectional area of 5  10 3 m 2 , doped one side with boron concentration of 5  1015 cm 3 and
on the other side with arsenic at concentration of 2  1017 cm 3 . The reverse bias is 5 V.
(i)
Built-in potential at 300 K and 400 K.
(ii)
Depletion layer width on both sides of the junction
(iii) Minority carrier concentration on both sides.
(iv)
Electric field profile
(v)
Energy band diagram under reverse bias.
Text book problems:
2.104, 3.9, 3.10