A.) B.) = 0.995 0.995 = 212.63 1 212.63 20 = 0.906 = 90.6% 20

SOLUTIONS:

Problem 1:

A.)

=

=

1.00 1.050

=

20 21

= 1 - = 20

B.)

=

1.001.01 1.0250(1-.01)

=

0.995

0.995 = 1 - 0.995 = 212.63

212.63 - 20

=

20

= 0.906 = 90.6%

Problem 2:

=

=

1.00 20

=

50

=

=

1.00 1.0025 50 0.9975

=

20.1

20.1 - 20 = 20 = 0.00501 = 0.501%

Problem 3:

Assume BJT works in forward active region and the capacitors are very large so they can be treated as open circuits.

8 - 0.6 = 400 = 18.5 = = 100 18.5 = 1.85 = 10 - 4000 0.00185 = 0.6 = 0 (there is a capacitor creating an open circuit in DC. )

Problem 4:

For the MOSFET to be in saturation -

+ 2 2 - 0.5 -0.5

=

2

(

-

)2

=

4

- 1

300

10-6

8 4

(0

-

(-2)

-

0.5)2

=

4

- 1

= 4 - 0.00135 1 -0.5

1 3.33

Problem 5:

Assuming that 1 and 2 are in saturation

1

=

2

2

(

-

)2

=

2

(

- )2

300

10-6 22

10

(0

-

(-2)

-

0.5)2

=

75

10-6 21

50

-

2

-

(-0.5)2

= 0.55 or 0.816. Since output has to be VDD Vout VSS we will choose 0.55 V

Problem 6:

For quiescent values that capacitors act as open circuits, so the voltage is simply,

=

28 - 90K

-

10K

=

28 - 10 90K

= ( + 1)

=

(101)

28

-

10

( 90K

+

0.6)

=

2K

0.4 V

=

1 V

1 = IE = 0.99 2000 = 495 ? = 28 - 4000 = 26.02 V = 0

Problem 7:

a)for the same voltage drop, the ratio of currents between two BJT is a the same as the ratio of

their areas (you can verify that to yourself) 1 = 1 = 1

2 2 5

= 1 + 2 = 6 1

= 1 + = 1 + 61

1

5

1 = + 6 -> = 2 = 51 = + 6

Assuming that is large = 5 = 7.5

b) Similarly to part (a), for two transistors in saturation with the same VGS, their currents will be

a ratio of their W/L

1

1 2

=

1 2

=

5 20

=

1 4

2

= 4 = 6

Problem 8:

:

=

2 1

2

:

=

2 1

1

These are very useful structures that are called "Current mirrors". They allow current to be mirrored over to other branches with a gain that is dependent on the geometric ratios of MOSFETS/BJT's used.

Problem 9: Code:

TestBench:

Waveform Output:

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download