Section 7: Measuring I-V characteristics of FETs
Model 2450 Interactive SourceMeter® Instrument User's Manual
7-12
2450-900-01 Rev. A / June 2013
Using TSP commands in a linear sweep to set up the test
In this example, the code steps the gate-source voltage, sweeps the drain-source voltage at each
step, and measures the drain-source current. The parameters for this example are:
•
SMU-1 (drain) is the sweeper and master node (set to node 1)
•
Starting step voltage: 0 V
•
Stopping step voltage: 5 V
•
Number of steps: 51
•
SMU-2 (gate) is the stepper and subordinate node 2
•
Starting step voltage: 2 V
•
Stopping step voltage: 5 V
•
Number of steps: 4
Send the following commands for this example application:
--Reset the instruments and the TSP-Link connection, and clear the buffers.
tsplink.initialize()
reset()
node[2].reset()
--If the TSP-Link state is not online, print an error message and quit.
state = tsplink.state
if state ~= "online" then
print("Error:\n-Check that all SMUs have a different node number")
print("-Check that all SMUs are connected correctly\n")
return
end
--Set the number of sweep points (also used for printing).
num = 51
--######################## Model 2450 #1 (drain) setup ################
--Set up the source function.
smu.source.func = smu.FUNC_DC_VOLTAGE
smu.source.ilimit.level = 300e-3
smu.source.autorange = smu.ON
--Set up the measure function.
smu.measure.func = smu.FUNC_DC_CURRENT
smu.measure.autorange = smu.ON
smu.measure.terminals = smu.TERMINALS_REAR
--Set up a linear sweep.
smu.source.sweeplinear('MOSFET', 0, 5, num, 0.001)
--########################## Model 2450 #2 (gate) setup ################
--Set up the source function.
node[2].smu.source.func = node[2].smu.FUNC_DC_VOLTAGE
node[2].smu.source.autorange = node[2].smu.ON
node[2].smu.source.ilimit.level = 100e-3
--Set up the measure function.
node[2].smu.measure.func = node[2].smu.FUNC_DC_CURRENT
node[2].smu.measure.autorange = node[2].smu.ON
node[2].smu.measure.terminals = node[2].smu.TERMINALS_REAR
