CMOS VLSI Design Exam 1 UPDATED
ACTUAL Exam Questions and CORRECT
Answers
n type - CORRECT ANSWER - A class of extrinsic semiconductors containing dopant
atoms with more than four valence electrons, allowing for extra electrons to provide more
conductivity
p type - CORRECT ANSWER - A class of extrinsic semiconductors containing dopant
atoms with fewer than four valence electrons., has a "hole" that decreases conductivity. acts as a
positive carrier
diode - CORRECT ANSWER - junction between p and n type silicone
PMOS, NMOS, CMOS stands for - CORRECT ANSWER - Positive-channel Metal Oxide
Semiconductor, negative-channel, and complementary
MOSFET stands for - CORRECT ANSWER - Metal Oxide Semiconductor Field Effect
Transistor
nmos passes strong - CORRECT ANSWER - strong 0s and degrades 1
pmos passes strong - CORRECT ANSWER - strong 1s and degrades 0
transmission gate - CORRECT ANSWER - pmos and nmos connected in parallel that will
turn on when 1 is input and 0 when 0 is input and it passes both well
double rail logic - CORRECT ANSWER - when both the control inout and complement
are req by transmission gate
, fully restored logic gate - CORRECT ANSWER - when nmos only needs to pass 0 and
pmos only needs to pass 1 in complementary static cmos design so both strong 0 and 1 are
transmitted by it
tristate buffer - CORRECT ANSWER - A buffer that allows for three states: High, Low,
and High Impedance. It effectively acts as a switch that is closed when an enable bit is set. It has
two inputs. Is frequently used to control data on the data bus.
pmos is a good conductor of - CORRECT ANSWER - 1s
nmos is a good conductor of - CORRECT ANSWER -0
cmos is - CORRECT ANSWER - complementary metal-oxide semiconductor
the majority carriers in ntype si are ______ and the minority are _____ - CORRECT
ANSWER - electrons majority, holes minority (and vise vera for ptype)
threshold voltage of a mosfet - CORRECT ANSWER - threshold voltage Vt is the
minimum gate to source voltage above which the nmos begins to conduct, or below which the
pmos begins to conduct
why do we draw the length of a cmos transistor equal to the minimum allowable length in a
technology - CORRECT ANSWER - Ids is inversely proportional to the length. usually we
design for fast gates, so we keep min allowable gates for good Ids
pure silicone is a good conductor of electricity? T/F - CORRECT ANSWER - false, its bad
in a static cmos circuit, ______ section is responsible for pulling the output to a logical 1 -
CORRECT ANSWER - PMOS (and NMOS pulls to gnd)
ACTUAL Exam Questions and CORRECT
Answers
n type - CORRECT ANSWER - A class of extrinsic semiconductors containing dopant
atoms with more than four valence electrons, allowing for extra electrons to provide more
conductivity
p type - CORRECT ANSWER - A class of extrinsic semiconductors containing dopant
atoms with fewer than four valence electrons., has a "hole" that decreases conductivity. acts as a
positive carrier
diode - CORRECT ANSWER - junction between p and n type silicone
PMOS, NMOS, CMOS stands for - CORRECT ANSWER - Positive-channel Metal Oxide
Semiconductor, negative-channel, and complementary
MOSFET stands for - CORRECT ANSWER - Metal Oxide Semiconductor Field Effect
Transistor
nmos passes strong - CORRECT ANSWER - strong 0s and degrades 1
pmos passes strong - CORRECT ANSWER - strong 1s and degrades 0
transmission gate - CORRECT ANSWER - pmos and nmos connected in parallel that will
turn on when 1 is input and 0 when 0 is input and it passes both well
double rail logic - CORRECT ANSWER - when both the control inout and complement
are req by transmission gate
, fully restored logic gate - CORRECT ANSWER - when nmos only needs to pass 0 and
pmos only needs to pass 1 in complementary static cmos design so both strong 0 and 1 are
transmitted by it
tristate buffer - CORRECT ANSWER - A buffer that allows for three states: High, Low,
and High Impedance. It effectively acts as a switch that is closed when an enable bit is set. It has
two inputs. Is frequently used to control data on the data bus.
pmos is a good conductor of - CORRECT ANSWER - 1s
nmos is a good conductor of - CORRECT ANSWER -0
cmos is - CORRECT ANSWER - complementary metal-oxide semiconductor
the majority carriers in ntype si are ______ and the minority are _____ - CORRECT
ANSWER - electrons majority, holes minority (and vise vera for ptype)
threshold voltage of a mosfet - CORRECT ANSWER - threshold voltage Vt is the
minimum gate to source voltage above which the nmos begins to conduct, or below which the
pmos begins to conduct
why do we draw the length of a cmos transistor equal to the minimum allowable length in a
technology - CORRECT ANSWER - Ids is inversely proportional to the length. usually we
design for fast gates, so we keep min allowable gates for good Ids
pure silicone is a good conductor of electricity? T/F - CORRECT ANSWER - false, its bad
in a static cmos circuit, ______ section is responsible for pulling the output to a logical 1 -
CORRECT ANSWER - PMOS (and NMOS pulls to gnd)
