2606B System SourceMeter® Instrument Reference Manual
Section 2: General operation
2606B-901-01 Rev. B / May 2018
2-59
The following figures illustrate using three channels to test the same 3-terminal N-channel JFET
device. The third channel is connected to the source (S) terminal of the JFET. This allows the source
terminal to be biased above signal LO. Setting this SMU to output 0 V effectively connects the source
terminal of the JFET to signal LO.
Figure 32: Three channels connected to a 3-terminal device
Guarding and shielding
You can optimize source-measure performance and safety with the effective use of guarding and
shielding (noise and safety shields).
Safety shield
A safety shield must be used whenever hazardous voltages (>30 V
RMS
, 42 V
PEAK
) will be
present in the test circuit. To prevent electrical shock that could cause injury or death, never
use the 2606B in a test circuit that may contain hazardous voltages without a properly
installed and configured safety shield.
The safety shield can be metallic or nonconductive, and must completely surround the DUT test
circuit. A metal safety shield must be connected to a known protective earth (safety ground). See
(on page 2-62) for important safety information on the use of a metal or a nonconductive
enclosure.