Keithley 4200-SCS Reference Manual page 72

Section 3: Source-Measure Hardware
CAUTION
FORCE terminal
The FORCE terminal is a standard triaxial connector used as a return path for the SMU or preamp
FORCE current. The center pin is FORCE, the inner shield is GUARD, and the outer shield is
circuit COMMON.
NOTE
SENSE terminal
The SENSE terminal is a standard triaxial connector used to apply the ground unit SENSE signal
to the DUT in a remote sense application. The center pin is SENSE, the inner shield is GUARD,
and the outer shield is circuit COMMON. When the ground unit SENSE signal is connected to a
DUT, all SMU/Preamp measurements will be made relative to this DUT connection.
COMMON terminal
The COMMON terminal is a binding post that provides access to circuit COMMON.
NOTE
Chassis ground
This binding post provides a convenient connecting point to system chassis ground for purposes
of shielding a test fixture.
Figure 3-21
Chassis ground
3-22
The maximum allowed voltage between circuit COMMON and chassis ground
is ±32V DC.
The ground unit FORCE and GUARD signal terminals are connected to circuit
COMMON.
Normally, a link is connected between ground unit COMMON and chassis ground, but it
may be necessary to remove the link to avoid measurement problems caused by ground
loops or electrical interference. See the
S
E
N
S
E
F
O
R
C
E
C
O
M
M
O
N
Chassis (Earth) Ground
Return to
Interference, page 5-25
GNDU
INSTRUMENT
CONNECTIONS
SMU ONLY
SENSE LO
GUARD
SENSE LO
COMMON
SMU AND GNDU
SENSE
COMMON
GUARD
FORCE
Section Topics
Model 4200-SCS Reference Manual
for details.
SLOT
8
4200-901-01 Rev. S / May 2017