<s>
Transconductance	B-Algorithm
(	O
for	O
transfer	B-Algorithm
conductance	I-Algorithm
)	O
,	O
also	O
infrequently	O
called	O
mutual	B-Algorithm
conductance	I-Algorithm
,	O
is	O
the	O
electrical	O
characteristic	O
relating	O
the	O
current	O
through	O
the	O
output	O
of	O
a	O
device	O
to	O
the	O
voltage	O
across	O
the	O
input	O
of	O
a	O
device	O
.	O
</s>
<s>
Transadmittance	B-Algorithm
(	O
or	O
transfer	O
admittance	O
)	O
is	O
the	O
AC	O
equivalent	O
of	O
transconductance	B-Algorithm
.	O
</s>
<s>
Transconductance	B-Algorithm
is	O
very	O
often	O
denoted	O
as	O
a	O
conductance	O
,	O
gm	O
,	O
with	O
a	O
subscript	O
,	O
m	O
,	O
for	O
mutual	O
.	O
</s>
<s>
The	O
SI	O
unit	O
for	O
transconductance	B-Algorithm
is	O
the	O
siemens	O
,	O
with	O
the	O
symbol	O
S	O
,	O
as	O
in	O
conductance	O
.	O
</s>
<s>
Transresistance	O
(	O
for	O
transfer	O
resistance	O
)	O
,	O
also	O
infrequently	O
referred	O
to	O
as	O
mutual	O
resistance	O
,	O
is	O
the	O
dual	O
of	O
transconductance	B-Algorithm
.	O
</s>
<s>
Transimpedance	O
(	O
or	O
,	O
transfer	O
impedance	O
)	O
is	O
the	O
AC	O
equivalent	O
of	O
transresistance	O
,	O
and	O
is	O
the	O
dual	O
of	O
transadmittance	B-Algorithm
.	O
</s>
<s>
For	O
vacuum	O
tubes	O
,	O
transconductance	B-Algorithm
is	O
defined	O
as	O
the	O
change	O
in	O
the	O
plate	O
(	O
anode	O
)	O
current	O
divided	O
by	O
the	O
corresponding	O
change	O
in	O
the	O
grid/cathode	O
voltage	O
,	O
with	O
a	O
constant	O
plate(anode )	O
to	O
cathode	O
voltage	O
.	O
</s>
<s>
Similarly	O
,	O
in	O
field	O
effect	O
transistors	B-Application
,	O
and	O
MOSFETs	B-Architecture
in	O
particular	O
,	O
transconductance	B-Algorithm
is	O
the	O
change	O
in	O
the	O
drain	O
current	O
divided	O
by	O
the	O
small	O
change	O
in	O
the	O
gate/source	O
voltage	O
with	O
a	O
constant	O
drain/source	O
voltage	O
.	O
</s>
<s>
Typical	O
values	O
of	O
for	O
a	O
small-signal	O
field	O
effect	O
transistor	B-Application
are	O
1	O
to	O
30	O
millisiemens	O
.	O
</s>
<s>
Using	O
the	O
Shichman	O
–	O
Hodges	O
model	O
,	O
the	O
transconductance	B-Algorithm
for	O
the	O
MOSFET	B-Architecture
can	O
be	O
expressed	O
as	O
(	O
see	O
MOSFET	B-Architecture
article	O
)	O
:	O
</s>
<s>
The	O
overdrive	O
voltage	O
(	O
sometimes	O
known	O
as	O
the	O
effective	O
voltage	O
)	O
is	O
customarily	O
chosen	O
at	O
about	O
70	O
–	O
200mV	O
for	O
the	O
65	B-Algorithm
nm	I-Algorithm
technology	O
node	O
(	O
≈	O
1.13mA/μm	O
of	O
width	O
)	O
for	O
a	O
of	O
11	O
–	O
32mS/μm	O
.	O
</s>
<s>
The	O
of	O
bipolar	O
small-signal	O
transistors	B-Application
varies	O
widely	O
,	O
being	O
proportional	O
to	O
the	O
collector	O
current	O
.	O
</s>
<s>
The	O
input	O
impedance	O
is	O
the	O
current	O
gain	O
(	O
)	O
divided	O
by	O
the	O
transconductance	B-Algorithm
.	O
</s>
<s>
For	O
most	O
transistors	B-Application
in	O
linear	O
operation	O
it	O
is	O
well	O
below	O
100	O
µS	O
.	O
</s>
<s>
A	O
transconductance	B-Algorithm
amplifier	I-Algorithm
(	O
g	O
amplifier	O
)	O
puts	O
out	O
a	O
current	O
proportional	O
to	O
its	O
input	O
voltage	O
.	O
</s>
<s>
In	O
network	O
analysis	O
,	O
the	O
transconductance	B-Algorithm
amplifier	I-Algorithm
is	O
defined	O
as	O
a	O
voltage	O
controlled	O
current	O
source	O
(	O
VCCS	O
)	O
.	O
</s>
<s>
An	O
operational	O
transconductance	B-Algorithm
amplifier	I-Algorithm
(	O
OTA	O
)	O
is	O
an	O
integrated	O
circuit	O
which	O
can	O
function	O
as	O
a	O
transconductance	B-Algorithm
amplifier	I-Algorithm
.	O
</s>
<s>
These	O
normally	O
have	O
an	O
input	O
to	O
allow	O
the	O
transconductance	B-Algorithm
to	O
be	O
controlled	O
.	O
</s>
