Set Up The Application Using Scpi Commands In A Linear Sweep - Keithley Interactive SourceMeter 2450 User Manual

Section 7: Measuring I-V characteristics of FETs

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
SMU 2
SMU 1
SMU 2
Pseudocode vds = []
7-8
Commands
*RST
SENS:FUNC "CURR"
SENS:CURR:RANG:AUTO ON
ROUT:TERM REAR
SOUR:FUNC VOLT
SOUR:VOLT:RANG 20
*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
OUTP ON
ids = []
for i = 2, 5 do:
Model 2450 Interactive SourceMeter® Instrument User's Manual
Description
• 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.
• 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.
• Turn on the output.
• 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).
2450-900-01 Rev. C / December 2013