1-1
Section 1
General Information
1.1 Introduction
The following paragraphs discuss the overall hardware and soft-
ware configurations of the system necessary to run the example
application programs in this guide.
1.2 Hardware Configuration
1.2.1 System Configuration
Figure 1-1 shows the overall hardware configuration of a typical
test system. The various components in the system perform a
number of functions:
Series 2600 System SourceMeter Instruments: System Source -
Meter instruments are specialized test instruments capable
of sourcing current and simultaneously measuring voltage, or
sourcing current and simultaneously measuring voltage. A single
Source-Measure Unit (SMU) channel is required when testing two-
terminal devices such as resistors or capacitors. Three- and four-
terminal devices, such as BJTs and FETs, may require two or more
SMU channels. Dual-channel System SourceMeter instruments,
such as the Models 2602, 2612, and 2636, provide two SMUs in a
half-rack instrument. Their ease of programming, flexible expan-
sion, and wide coverage of source/measure signal levels make
them ideal for testing a wide array of discrete components. Before
starting, make sure the instrument you are using has the source
and measurement ranges that will fit your testing specifications.
Test fixture: A test fixture can be used for an external test circuit.
The test fixture can be a metal or nonmetallic enclosure, and is
typically equipped with a lid. The test circuit is mounted inside
the test fixture. When hazardous voltages (>30Vrms, 42Vpeak)
will be present, the test fixture must have the following safety
requirements:
WARNING
To provide protection from shock hazards, an enclo-
sure should be provided that surrounds all live
parts. Nonmetallic enclosures must be constructed
of materials suitably rated for flammability and
the voltage and temperature requirements of the
test circuit. For metallic enclosures, the test fixture
chassis must be properly connected to safety earth
ground. A grounding wire (#18 AWG or larger)
must be attached securely to the test fixture at a
screw terminal designed for safety grounding. The
other end of the ground wire must be attached to a
known safety earth ground.
Construction Material: A metal test fixture must be connected to a
known safety earth ground as described in the WARNING above.
WARNING
A nonmetallic test fixture must be constructed
of materials that are suitable for flammability,
voltage, and temperature conditions that may exist
in the test circuit. The construction requirements
for a nonmetallic enclosure are also described in
the WARNING above.
Test Circuit Isolation: With the lid closed, the test fixture must
completely surround the test circuit. A metal test fixture must be
electrically isolated from the test circuit. Input/output connectors
mounted on a metal test fixture must also be isolated from the test
fixture. Internally, Teflon
®
standoffs are typically used to insulate
the internal pc-board or guard plate for the test circuit from a
metal test fixture.
Interlock Switch: The test fixture must have a normally open inter-
lock switch. The interlock switch must be installed so that, when
the lid of the test fixture is opened, the switch will open, and
when the lid is closed, the switch will close.
WARNING
When an interlock is required for safety, a separate
circuit should be provided that meets the require-
ments of the application to protect the operator reli-
ably from exposed voltages. The output enable pin
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