Model 2651A High Power System SourceMeter® Instrument User's Manual Section 7: Increasing SMU current sourcing ability
--[[
Name: DualSmuRdson(gateLevel, dstart, dstop, dsteps, pulseWidth,
pulsePeriod, pulseLimit)
Description: This function uses two 2651A SMUs to perform a pulsed Rds(on)
sweep with currents up to 100A.
Parameters:
gateLevel: The gate level to be used during the sweep
dstart: The starting current level of the drain sweep
dstop: The ending current level of the drain sweep
dsteps:
The number of steps in the drain sweep
pulseWidth: The width of the drain pulse in seconds
pulsePeriod: The time from the start of one drain pulse to
the next in seconds
pulseLimit: The voltage limit of the drain pulse in volts
Note: Actual pulse limit will be 10% lower than setting
to protect SMUs in a compliance condition
Example Usage:
DualSmuRdson(10, 1, 100, 100, 500e-6, 50e-3, 10)
]]
function DualSmuRdson(gateLevel, dstart, dstop, dsteps, pulseWidth, pulsePeriod,
pulseLimit)
tsplink.reset(3) -- Verify that at least three nodes are present
reset()
-- Configure 2651A #1 (Drain SMU 1)
-----------------------------------
smua.reset()
smua.source.func
= smua.OUTPUT_DCAMPS
smua.sense
=
smua.SENSE_REMOTE
smua.source.offmode
= smua.OUTPUT_NORMAL
smua.source.offfunc
= smua.OUTPUT_DCVOLTS
smua.source.offlimiti
= 1e-3 -- Set off limit
-- SMU #1 will be a 0V voltage source with 1mA limit when its
-- output is turned off. SMU #2 will be a 0A current source with
-- a 10V limit when the output is turned off. These settings keep
-- the parallel combination safe in case one SMU is turned off.
smua.source.rangei = math.max(math.abs(dstart / 2), math.abs(dstop / 2))
smua.source.leveli
= 0
-- Sets the DC bias level
smua.source.limitv
= 9
-- Sets the DC bias limit
-- SMU #2 will have a voltage limit of 10V. By setting the voltage
-- limit 10% lower than that of SMU #2, we can ensure that only
-- one of the two SMUs will ever go into compliance and become a
-- voltage source. This is desirable, because if both SMUs went
-- into compliance, there would be two voltage sources in parallel,
-- which is an unsafe condition.
smua.measure.nplc
= 0.005
smua.measure.rangev
= pulseLimit
smua.measure.autozero
= smua.AUTOZERO_ONCE
smua.measure.delay =
pulseWidth - ((1 / localnode.linefreq) * smua.measure.nplc)) - 20e-6
2651A-900-01 Rev. A / March 2011
7-11
