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Section 7: Measuring I-V characteristics of FETs
Model 2450 Interactive SourceMeter® Instrument User's Manual
7-8
2450-900-01 Rev. C / December 2013
Set up the application using SCPI commands in a linear sweep
In this example, the gate voltage steps from 2 V to 6 V in 1 V steps, the drain voltage sweeps from
0 V to 5 V in 51 steps, and the drain current is measured. The application retrieves each of 51
readings and source values from
defbuffer1
and saves them in the arrays
vds
and
ids
,
respectively.
You send commands to either the sweeper (SMU 1) or the stepper (SMU 2). In the table, the
commands for the sweeper are shown with a light gray background. The commands for the stepper
are shown with a darker gray background. The light-brown shaded code represents pseudocode that
will vary depending on the programming environment you use. Each bulleted item in the Description
column describes a single line of code in the Commands column.
Send the following commands for this application:
SMU 1,
SMU 2, or
pseudocode
Commands
Description
SMU 2
*RST
SENS:FUNC "CURR"
SENS:CURR:RANG:AUTO ON
ROUT:TERM REAR
SOUR:FUNC VOLT
SOUR:VOLT:RANG 20
•
Reset the instrument.
•
Set to measure current.
•
Set to measure with autorange enabled.
•
Set to use rear terminals.
•
Set to source voltage.
•
Set to 20 V source range.
SMU 1
*RST
SENS:FUNC "CURR"
SENS:CURR:RANG:AUTO ON
ROUT:TERM REAR
SOUR:FUNC VOLT
SOUR:VOLT:RANG 20
SOUR:VOLT:ILIM 1
SOUR:SWE:VOLT:LIN 0, 5, 51, 0.01
•
Reset the instrument.
•
Set to measure current.
•
Set to measure with autorange enabled.
•
Set to use the rear terminals.
•
Set to source voltage.
•
Set to the 20 V source range.
•
Set the source limit to 1 A.
•
Set up a linear sweep from 0 V to 5 V in 51
steps, with a delay of 10 ms.
SMU 2
OUTP ON
•
Turn on the output.
Pseudocode
vds = []
ids = []
for i = 2, 5 do:
•
Create an empty array to hold measured
voltage values.
•
Create an empty array to hold measured
current values.
•
Set up a
for
loop from 2 to 5 (inclusive).