Keithley 2600a series - Figure 2-14 Model 2636 A, Two Smus Connected to a 3-Terminal Device (Local Sensing, Floating)

2600AS-901-01 Rev. B / September 2008 Return to Section Topics 2-11
Series 2600A System SourceMeter® Instruments Reference Manual Section 2: DUT Test Connections
Figure 2-14
Model 2636A, two SMUs connected to a 3-terminal device (local sensing, floating)
Figure 2-15 shows how to use three SMUs to test the same 3-terminal device. The third SMU is
connected to the source (S) terminal of the JFET. This allows the source terminal to be biased
above signal low. Setting this SMU to output 0V effectively connects the source terminal of the
JFET to signal low.
Figure 2-15
Three SMUs connected to a 3-terminal device
G
S
D
N-Channel
JFET
Keithley Model 2602A/2612A-1
Channel
A
LO G
Lo
HI G G G
HI
SS
Channel
B
LOG
Lo
HIGGG
HI
SS
HI HI
Keithley Model 2602A/2612A-2
Channel
A
LO G
Lo
HI G G G
HI
SS
Channel
B
LOG
Lo
HIGGG
HI
SS
HI
G
S
D
Equivalent Circuit
SMU B
Unit #1
HI
LO
SMU A
Unit #2
HI
LO
SMU A
Unit #1
HI
LO