Keithley 7709, User Manual

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5
Rows 3 through 6
As shown in Figure 1 , channels 17 through 48 are the channels for Rows 3 through 6. These channels can only be closed using
multiple channel operation (
ROUT:MULT:CLOS
command). For system channel operation, these channels are invalid (cannot
be closed).
WARNING Multiple channel operation should only be performed by experienced test engineers who
recognize the dangers associated with multiple channel closures.
CAUTION When closing multiple channels, it is possible to connect incompatible test equipment
and/or DUTs causing high currents to flow. This can cause serious damage to test equip-
ment and DUTs.
Rows 3 through 6 are used to connect one or more external sources to the test system. An external source is typically used to
power DUT. To prevent overloading of the external source, each DUT can be powered separately. An example of this is shown
in
Figure 4 . The external source is connected to Row 3 and the power cables for the two DUTs are connected to Columns 1 and
2.
As shown in Figure 4 , DUT 1 is tested by closing system channel 3 and multiple channel 17. To test DUT 2, the following
sequence would be used:
1. Open multiple channel 17 to remove power from DUT 1.
2. Close multiple channel 18 to apply power to DUT 2.
3. Close system channel 4 to connect DUT 2 to the DMM (channel 3 opens automatically).
Figure 4
Adding an external source to the test system
HI
LO
Input
HI
LO
Sense
9 10 11 12 13 14 15 16
50
49
1 2
3
4 5 6 7
8
HI
LO
Row 1
DUT
1
DMM*
Col 1
HI LO HI LO HI LO HI LO HI LO HI LO HI LO HI LO
Col 2
Col 3 Col 4 Col 5
Col 6 Col 7 Col 8
HI
LO
Row 2
HI
LO
Row 3
External
Source
DUT
2
Multiple channel 17 closed to power DUT 1.
System channel 3 closed to connect DUT 1 to DMM Input.
17 18 19 20
21
22
23
24
*2-wire
function
selected.