Keithley 2600B

Section
3: Functions and features Series 2600B System SourceMeter® Instrument Reference M
anual
3-26 2600BS-901-01 Rev. C / August 2016
In this example:
A = 0, V
start
= 1, V
end
= 10, N = 5
Using the formula above, k = 1
Step size (b) for the sweep in the above figure is calculated as follows:
Figure 57: Logarithmic staircase sweeps (2)
Log Step Size
log10(stop-0) log10(start-0)
–
Points
1
–
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-
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-
--
--
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--
--
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----------------------------------------
--
-
--
--
-
-
-
-
-
-
-
-
-
-=
log10(10)
log10(1)–
5 1
–
---------------------------------
-
--
--
-
-
-
-
-
-
-
-
-
-
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-
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-
=
1 0–(
)
4
-
----
---
---
---
---=
0.25
=


 


 
 
 
 
 
 


Therefore, b = 10
(log step size)
= 1.7783
The five log steps for this sweep are listed in the Logarithmic sweep points table below.
Logarithmic sweep points
Source point (N) Source level (V) Step number (i)
1
1
0
2
1.7783
1
3 3.1623 2
4
5.6234
3
5
10
4
When this sweep starts, the output will go to the start level (1 V) and sweep through the symmetrical
log points.
To configure a logarithmic staircase sweep, use the smuX.trigger.source.logY()function. This
function configures the source values the source-measure unit (SMU) will output when performing a
logarithmic sweep. After configuring the sweep, you must also enable the source action by setting the
following attribute:
smuX.trigger.source.action