Connections
2-9
•
The Model 6430 will perform to rated specification with up to 1V drop per source lead
on the 100µA through 100mA ranges. On the 10µA range and below (when using the
Remote PreAmp), the allowable voltage drop in each source lead is limited as follows:
Guarding methods
Cable guard
Use the high-impedance (cable) guard connection scheme shown in Figure 2-4 for the fol-
lowing source-measure condition:
•
Test circuit impedance is >1G
Ω
.
Cable guard is always available at the Remote PreAmp. If not using the Remote PreAmp,
use the V,
Ω
GUARD banana jack on the mainframe with CABLE guard selected. See
Guard
selection
to select cable guard.
A test fixture is typically used when testing high-impedance devices. The test fixture reduces
noise and protects the user from a potentially hazardous voltage on the guard shield (or plate).
See
Section 5, Guard
for details on using guard.
Note that the test fixture chassis is connected to In/Out LO to reduce noise.
Current range
Maximum allowable resistance
per source lead
10µA
1µA
100nA
10nA
1nA
100pA
10pA
1pA
10
Ω
50
Ω
500
Ω
5k
Ω
50k
Ω
1M
Ω
50M
Ω
1G
Ω
Guard
Shield
Triax Cable
Test Fixture
HI
LO
Connect to earth
safety ground using
#18 AWG wire or
larger
DUT
WARNING Guard is at the same voltage level as
input/output high. Therefore, if a
hazardous voltage (
≥
42V peak) is
present on input/output high, it is also
present on the guard terminals of the
Remote PreAmp and mainframe.
6430
REMOTE
PreAmp
SENSE
MAINFRAME
Connect to
REMOTE PreAmp
connector on rear
panel of mainframe
Guard
IN/OUT
HIGH
Preamp Cable*
KEITHLEY
*Keithley part number: CA-176-1D.
Figure 2-4
High-impedance
guarding
Summary of Contents for 6430
Page 26: ......
Page 32: ......
Page 78: ...2 14 Connections ...
Page 98: ...3 20 Basic Source Measure Operation ...
Page 138: ...5 30 Source Measure Concepts ...
Page 156: ...6 18 Range Digits Speed and Filters ...
Page 168: ...7 12 Relative and Math ...
Page 176: ...8 8 Data Store ...
Page 202: ...9 26 Sweep Operation ...
Page 248: ...11 22 Limit Testing ...
Page 310: ...16 6 SCPI Signal Oriented Measurement Commands ...
Page 418: ...17 108 SCPI Command Reference ...
Page 450: ...18 32 Performance Verification ...
Page 477: ...A Specifications ...
Page 489: ...B StatusandErrorMessages ...
Page 498: ...B 10 Status and Error Messages ...
Page 499: ...C DataFlow ...
Page 503: ...D IEEE 488BusOverview ...
Page 518: ...D 16 IEEE 488 Bus Overview ...
Page 519: ...E IEEE 488andSCPI ConformanceInformation ...
Page 523: ...F MeasurementConsiderations ...
Page 539: ...G GPIB488 1Protocol ...
Page 557: ......