Keithley 7077, Инструкция по эксплуатации

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Operation
2-4
confined to the same matrix crosspoint. Each terminal of the
instrument can be connected to any matrix crosspoint. The
LO terminals of the matrix card are used as a shield. The clo-
sure of a single crosspoint will not connect an instrument to
a DUT.
2.3.3 Sensing
Figure 2-5 shows how the matrix card can be configured to
use instruments that have remote sensing capability. Sensing
is used to cancel the effects of matrix card path resistance
(<1.5) and the resistance of external cabling. Remote sensing
should be used when path resistance needs to be considered.
Figure 2-4
Differential switching example
A
A
A
A
A
A
HI
LO
Source or
Measure
7077
DUT
H
L
H
L
ROWS COLUMNS
System Common
Figure 2-5
Sensing example
A
A
A
A
Sense HI
Source HI
Sense LO
Source LO
Source or
Measure
7077
DUT
H
L
H
L
ROWS COLUMNS
2.3 Typical matrix switching schemes
The following paragraphs describe basic switching schemes
that are possible with a two-pole switching matrix.
2.3.1 Single-ended switching
In the single-ended switching configuration, the source or
measure instrument is connected to the DUT through a sin-
gle pathway as shown in Figure 2-3. The closure of a single
crosspoint will connect an instrument to a DUT.
2.3.2 Differential switching
The differential or floating switching configuration is shown
in Figure 2-4. The advantage of using this configuration is
that the terminals of the source or measure instrument are not
Figure 2-3
Single-ended switching example (using 4801 coaxial cable)
A
A
HI
Source or
Measure
7077
DUT
LO
H
L
ROW COLUMN
Shield