2 IN (A), THE TRANSISTOR SEES VGS = VDD AND VDS = VDS. THE CURRENT I...

2. - SOLUTIONS
SOLUTIONS

2.2 In (a), the transistor sees V

gs

= V

DD

and V

ds

= V

DS

. The current is

I = β    V − − V V    V

DS DD t DS DS1

2 2

In (b), the bottom transistor sees V

gs

= V

DD

and V

ds

= V

1

. The top transistor sees V

gs

= V

DD

- V

1

and V

ds

= V

DS

- V

1

. The currents are

V V

I = β    V − − V V    V = β    V − V − − V −    V − V

( ) (

1

) ( )

DS2 1 1 1 1DS DD t DD t DS

2 2

Solving for V

1

, we find

V = V − V − V − V −    V − − V V    V

( ) ( )

21

2

DD t DD t DD t DS

Substituting V

1

indo the I

DS2

equation and simplifying gives I

DS1

= I

DS2

.