This preview shows page 1. Sign up to view the full content.
Unformatted text preview: the lower
transistor,
0, so
0.5 ; for the upper transistor,
,
0.5 . We assume both devices are in triode,
so
denoting the voltage on the intermediate point as , then
1
2
1
2
Solving the equation, we get
0.609 Check our assumption, for lower NMOS,
1
; for upper NMOS,
1 assumption is correct.
1
2
For another NMOS with , 0.9 2.5 , then 130 ,
1 1
2 2 130 Then currents are equal as found above symbolically.
Note that if we use the body effect for the upper transistor, but ignore the
distributed body effect (no in current equations). The currents are not equal
(try it yourself).
2. As 0.1 , nMOS works in subthreshold region. Channel mobility of a 1017 cm3 doped bulk silicon is µn= µnbulk/2=400 cm2/Vs
''
Cox xd ox0
tox 7.1x107 F/cm2 2 si...
View
Full
Document
 Fall '08
 Taicheng
 Gate, Transistor, Volt

Click to edit the document details