Keithley 237

12V
e
>
8V
-
(J)
....
:::J
~
(J)
E
>
Voltage
Limit
Load
Line"
~'
·~0
o'V
\-o'll-
{)\)~
~(l(l
0.
lsource (Is)
Vm
=
Is•
R
=
(16mA)(500.a)
=8V
A.
Normal
1-Source
Operation
Operating
/point
Current
Source
/Load
Line
16mA
Figure
1-10.
!-Source
Operation
Examples
Source
V
Measure
I
The
operating
boundaries
in
a single
quandrant
for
Source V
Measure
I is
shown
in
Figure 1-11.
The
current
limit
load
line represents
the
programmed
compliance
limit
programmed
by
the
user.
The
voltage
source
load
line represents
the
source voltage
programmed
by
the
user. These
load
lines
are
boundary
lines
that
represent
the
operating
limits
of
the
Source
Measure
Unit
for
this
quadrant
of
operation.
The
operating
boundaries
for
the
other
three
quadrants
are
similar.
Where
on
the
boundary
the
Source
Measure
Unit
oper-
ates
depends
on
the
load
(DUT)
that
is connected to
its
output.
Figure 1-12
shows
operation
examples for resis-
tive
loads
that
are
soon
and
2000
respectively.
In
these
examples,
the
Source
Measure
Unit
is
programmed
to
source
10V
and
limit (measure) 2SmA.
In
Figure 1-12A,
the
Source
Measure
Unit
is sourcing 10V
to
the
soon
load
and
subsequently
measuring
20mA.
As
long
as
the
OUT
load
line intersects
the
voltage
source
load
line,
the
Source
Measure
Unit
will
be
able
to
source
its
programmed
voltage
(lOV).
+
+
e
>
-
SECTION1
Getting
Started
Voltage
Limit
Operating
Load
Line
" /
point
12V~--------~~~~~
Current
Source
/Load
Line
12mA
16mA
lsource (Is)
ls=Vrn!R
= 12V/1kn
=12mA
B.
1-Source
In
Compliance
Current
Limit
Load
Line
/
'
t
e?
Voltage
::J
(/)
.._
Source
as
Q)
Load
Line
E
-
'
V
source
/
Fi~ure
1-11.
V-Source
Operatin~
Boundaries
Figure
1-12B
shows
what
happens
if
the
resistance
of
the
load
is
decreased
to
2000.
The
OUT
load
line intersects
the
current
limit
load
line
placing
the
Source
Measure
Unit
in
compliance.
In
compliance,
the
Source
Measure
Unit
will
not
be
able
to
source
its
programmed
voltage
(10V).
Instead,
it
will
source
only
SV.
Notice
that
as
resistance decreases,
the
slope
of
the
DUT
load
line increases.
At
zero
resistance (shorted
output),
the
Source
Measure
Unit
will source virtually
OV
at
1-11