Keithley 237

SECTION2
Operation
2.6.4
General
Purpose
Matrix Cards
The Models 7052
and
7071
general
purpose
matrix cards
can
be
used
with
the
Source Measure
Unit
for
applica-
tions requiring 4-wire connections
to
DUT,
but
do
notre-
quire
low-current performance.
The Model 7052
is
a 4 x 5 matrix
that
is controlled
by
a
Model705
or
706
Scanner.
The
Model7071
is
an
8 x 12
ma-
trix
that
is controlled
by
the
Model707
Switching Matrix.
Both cards
have
3-pole switching
and
accommodate
con-
nections
with
screw terminals. Connections
to
the
Model
+
Triax/Unterminated
Cables
(3)
I
Output
HI
-
~~
1\
"'
H
::
u
,,
L
Guard
......
I
,,
~_,
G
......
,,
Sense
HI
~
//
(\
(\
;:
U I
Guard
-
''
t
::
H
I
L
Sense
LO
-
I
G
Output
LO
,
7071
can
also
be
made
using
the
38-pin
mass
terminated
connections.
Figure 2-25
shows
how
these
cards
can
be
connected to
the
Source
Measure
Unit
and
a test fixture for remote
sensing. Connections
to
the
Source
Measure
Unit
require
three
triax cables
that
are
unterminated
on
one
end. The
appropriate
conductors
at
the
unterminated
end
of
the
cables
are
connected directly
to
the
screw terminals
of
the
matrix card. Keep
in
mind
that
the
triax connectors
on
the
Source
Measure
Unit
are
3-lug, requiring 3-slot triax
ca-
bles
such
as
the
Model7078-TRX cables.
Note
that
cutting
one
triax cable
in
half
results
in
two
cables
that
are
unter-
minated
at
one
end.
::
,,
~
~:
,
~:
~
~~
Inner
Panel
connected
to
guard
_1
~---1
!
I
!
I
I
i
D
I
u
I
I
1
T
I
T
I
I
I
I
I
1-----1
;~a~
7052
or7071
Test Fixture
Output
LO
1
>-
k
/
;),
236/237/238
Matrix Card
CAUTION
To
prevent damage to
sw1tch1ng
cards,
do
not
switch
more than
200V
or
200mA.
Also,
incorrect crosspoint
closures
will
short various
signal
or
guard
lines
and
may
cause
instrument or
OUT
failure.
Figure
2-25.
Remote
Sense
Configuration
Using
Model7052
and
7071
(Guarded)
2-30
+
':'"
WARNING
:
To
avoid
electric
shock,
the test
fixture
chassis must be
connected
to
a safety earth ground.