Model 2450 Interactive SourceMeter® Instrument User's Manual
Section 7: Measuring I-V characteristics of FETs
2450-900-01 Rev. C / December 2013
7-7
SMU 2
*RST
SENS:FUNC "CURR"
SENS:CURR:RANG:AUTO ON
ROUT:TERM REAR
SOUR:FUNC VOLT
SOUR:VOLT:RANG 20
SOUR:VOLT:ILIM 1
SOUR:CONF:LIST:CRE "sweepVals"
DIG:LINE2:MODE TRIG, OUT
DIG:LINE1:MODE TRIG, IN
TRIG:DIG2:OUT:STIM NOT2
TRIG:DIG1:IN:CLE
TRIG:DIG1:IN:EDGE RIS
•
Reset the instrument.
•
Set to measure current.
•
Set to measure with autorange enabled.
•
Set to rear terminals.
•
Set to source voltage.
•
Set to 20 V source range.
•
Set the source limit to 1 A.
•
Create the source configuration list
sweepVals
.
•
Set digital line 2 to trigger out.
•
Set digital line 1 to trigger in.
•
Set the stimulus for digital line 2 to the
notify2
event.
•
Clear digital line 1.
•
Detect for a rising edge on line 1.
Pseudocode
for i = 0, 5, 0.1 do:
•
Set up a
for
loop from 0 to 5 in 0.1 steps
(inclusive).
SMU 2
SOUR:VOLT i
SOUR:CONF:LIST:STORE "sweepVals"
•
Set the voltage level to the iteration
number.
•
Store the source configuration to
sweepVals
.
Pseudocode
end for
•
End the
for
loop.
SMU 2
TRIG:BLOC:CONF:RECALL 1,
"sweepVals"
TRIG:BLOC:SOUR:STAT 2, ON
TRIG:BLOC:WAIT 3, DIG1
TRIG:BLOC:DEL:CONS 4, 0.01
TRIG:BLOC:MEAS 5
TRIG:BLOC:CONF:NEXT 6, "sweepVals"
TRIG:BLOC:BRAN:COUN 7, 51, 4
TRIG:BLOC:NOT 8, 2
TRIG:BLOC:BRAN:COUN 9, 4, 3
TRIG:BLOC:SOUR:STAT 10, OFF
•
Create a block to load
sweepVals
at the
first index.
•
Create a block to turn the output on.
•
Create a block to wait on digital line 3.
•
Create a block to delay for 0.01 seconds.
•
Create a block to take a measurement.
•
Create a block to load the next index of
sweepVals
.
•
Create a block to branch to block 4, 50
times.
•
Create a block to generate the notify2
event.
•
Create a block to branch to block 3 three
times.
•
Create a block to turn the output off.
SMU 1
INIT
•
Initiate the trigger model.
SMU 2
INIT
•
Initiate the trigger model.
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 (Including 5).
SMU 2
vds[i-1] = TRAC:DATA? 1 + 51*(i-
2), 51*(i-1), "defbuffer1", SOUR
vds[i-1] = TRAC:DATA? 1 + 51*(i-
2), 51*(i-1), "defbuffer1", READ
•
Save the sourced and measured values to
the arrays
vds
and
ids
, respectively. The
readings from each step are saved at each
index in the array.
Pseudocode
end for
•
End the
for
loop.