Cabling Requirements - Keithley 2790 User Manual

Model 2790 SourceMeter
CAUTION
Figure 4-1
Screw terminal access

Cabling requirements

General requirements — Cable wires should be mechanically durable, preferably
20AWG or larger with a high voltage insulation, such as rubber or silicon, good for at least
1000V.
It is the responsibility of the user to use the size and type of cable wire that best suits your
needs. Keep in mind that Teflon insulated wire performs better in high humidity condi-
tions, but it is not recommended when subjected to mechanical movement, like a device
handler.
Recommended cable wire — Beldon
size, with a thick rubber insulation rated for 5000V working voltage. It is very flexible and
mechanically durable.
NOTE
®
Switch System User's Manual
For the Model 7751/7753, be sure that the thermal pad is not dislodged.
Also be sure to use the correct cover with the integral heat sink to
assure proper voltage source operation. Note that earlier 7751 modules
do not have the pad or heat sink.
Heat Sink
(Underneath)
The use of an outer protective cable shield is recommended to prevent damage to
the wire insulation. It should preferably have a foil shield tied to earth ground
on one end to provide an extra layer of protection in the event that a wire
conductor becomes exposed. It will also serve to reduce measurement noise
caused by nearby machinery. A recommended cable shield is available from

Zippertubing and covered later in this section.
LOCK

8899 cable wire, which is stranded 18AWG in
Conductive
Thermal
Pad
BANK 1
SOURCE SENSE SRC SEN SRC SEN A B
GUARD HI LO HI LO HI HI LO LO
BANK 2
SRC SEN SRC SEN A B
HI HI LO LO
HI HI LO LO
SRC SEN SRC SEN A B
BANK 4
GND GND HI LO HI LO I / V IN OUT LO HI HI LO LO
INTERLOCK VSOURCE ISOURCE GUARD I / V SRC SEN SRC SEN A B
BANK 3
4-3