Configure two 2600B SMUs to get the maximum pulsed voltage level possible in Region 4:
40 V with 9 A source limit
SMU 1 configuration (sources one-half of the total pulse voltage):
Source function:
smua.source.func = smua.OUTPUT_DCVOLTS
Source range:
smua.source.rangev = 20
Idle (bias) source level (source level at base of pulse):
smua.source.levelv = -1e-12
Source polarity changes incur a 100 μs settling delay. Because the number 0 is treated as a positive
value in the 2600B, negative-going pulses with a 0 V bias level require the source to change polarity.
To ensure the proper pulse timing of SMU 1 and SMU 2, it is best to eliminate the SMU 1 polarity
changes and avoid the associated 100 μs time penalty. The easiest way to do this is set the bias
level to a negative value that is significantly less than the programming resolution of the instrument,
such as −1e−12. Functionally, this value is the same as zero, but it is mathematically negative, which
eliminates the polarity change.
Idle (bias) source limit (source limit at base of pulse):
smua.source.limiti = 1
Pulse source level (source level at top of pulse):
smua.trigger.source.listv({-20})
As explained in the note above, the polarity of SMU 1 is generally the opposite of the voltage polarity
across the device. To achieve a positive voltage across the device, program SMU 1 to a negative
voltage level. For example, to output 40 V across the device, program SMU 1 to −20 V and SMU 2 to
+20 V. To achieve a negative voltage across the device, program SMU 1 to a positive voltage level
and SMU 2 to a negative voltage level.
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