Figure 5-10 Test Circuit-Fixed H (Vary I) - Keithley 2182 User Manual

Figure 5-10
Test circuit—Fixed H (Vary I)
2182 #1
CH 1
HI
V
R
REF
100Ω
2182 #2
SourceMeter
CH 1
Source ±I
The readings in the buffer of Model 2182 #1 correspond to the current sweep values. You can
then use the buffer location numbers to reference DUT readings to current amplitudes:
Model 2182 #1 Buffer
RDG NO. 1 = 1mV ⇒ 10µA
RDG NO. 2 = 2mV ⇒ 20µA
RDG NO. 3 = 5mV ⇒ 50µA
Delta measurements — As previously explained, the DC current reversal measurement
technique must be used to cancel the effects of thermal EMFs in the test leads. By configuring
a custom sweep, the SourceMeter can function as a bipolar, growing amplitude source.
For example, if the test requires current steps of 10µA, 20µA, and 50µA, the 6- point custom
sweep would be configured as follows:
P0000 = +10µA
P0002 = +20µA
P0004 = +50µA
By enabling Delta measurements on the Model 2182, the effects of thermal EMFs in the test
leads will automatically be canceled during the source-measure process.
LO
1mA
HI
Thermal
V
EMFs
LO
Model 2182 #2 Buffer
RDG NO. 1 = DUT measurement
RDG NO. 2 = DUT measurement
RDG NO. 3 = DUT measurement
P0001 = –10µA
P0003 = –20µA
P0005 = –50µA
Ratio and Delta
30´ Cables
H DUT
<4K
Cryostat
5-23