Section 6: Characterization of power discretes
Model 2651A High Power System SourceMeter® Instrument User's Manual
smua.measure.autozero = smua.AUTOZERO_ONCE
smua.measure.nplc = 0.001
-- NPLC can be increased to improve measurement accuracy.
-- However, it should remain small enough to fit the measurement
-- within the width of the settled part of the pulse.
smua.measure.delay = (pulseWidth - ((1/localnode.linefreq) *
smua.measure.nplc)) - 50e-6
-- Set the measure delay so that the measurement is
-- taken at the end of the pulse before the falling edge
-- Timer 1 controls the pulse period
trigger.timer[1].count
= (dsteps <= 1) and 1 or (dsteps - 1)
-- If dsteps <= 1 then use 1 for the count else use dsteps - 1
trigger.timer[1].delay
= pulsePeriod
trigger.timer[1].passthrough = true
trigger.timer[1].stimulus
= tsplink.trigger[1].EVENT_ID
trigger.timer[1].clear()
-- Timer 2 controls the pulse width
trigger.timer[2].count
= 1
trigger.timer[2].delay
= pulseWidth - 3e-6
trigger.timer[2].passthrough = false
trigger.timer[2].stimulus
= smua.trigger.SOURCE_COMPLETE_EVENT_ID
trigger.timer[2].clear()
-- Configure Drain SMU(2651A) trigger model
smua.trigger.source.linearv(dstart, dstop, dsteps)
smua.trigger.source.limiti = pulseLimit
smua.trigger.measure.action = smua.ENABLE
smua.trigger.measure.iv(smua.nvbuffer1, smua.nvbuffer2)
smua.trigger.endpulse.action = smua.SOURCE_IDLE
smua.trigger.endsweep.action = smua.SOURCE_IDLE
smua.trigger.arm.count = gsteps
smua.trigger.count = dsteps
smua.trigger.arm.stimulus = 0
smua.trigger.source.stimulus = trigger.timer[1].EVENT_ID
smua.trigger.measure.stimulus = 0
smua.trigger.endpulse.stimulus = trigger.timer[2].EVENT_ID
smua.trigger.source.action = smua.ENABLE
-- Configure TSP-Link Triggers
tsplink.trigger[1].clear()
tsplink.trigger[1].mode = tsplink.TRIG_SYNCHRONOUSM
tsplink.trigger[1].stimulus = smua.trigger.ARMED_EVENT_ID
-- TSP-Link Trigger 1 is used by the 2651A to command the 26xxA
-- to step the gate and for the 26xxA to report to the 2651A
-- that it has completed the step.
tsplink.trigger[2].clear()
tsplink.trigger[2].mode = tsplink.TRIG_FALLING
tsplink.trigger[2].stimulus = smua.trigger.SWEEP_COMPLETE_EVENT_ID
-- TSP-Link Trigger 2 is used by the 2651A to command the 26xxA
-- that it has completed the drain sweep and that the 26xxA continue.
6-12
2651A-900-01 Rev. A / March 2011
