Pulse Delta Outputs - Keithley 6220 Reference Manual

Model 6220/6221 Reference Manual
Average power is then calculated as follows:
W (average power) = I x V x Duty Cycle
Example – Assume the following for Pulse Delta:
•
•
•
•
With Watts as the selected measurement units, the Peak power reading is calcu-
lated as follows:
W (peak power) = I x V
Average power is calculated as follows:
W (Average power) = I x V x Duty Cycle
Pulse Delta power calculation restriction
The algorithm for the Pulse Delta power calculation requires that the low pulse
level (I-Low) be very near zero. If the low pulse is more than ±6 counts (at 3-1/2
digit resolution) away from zero, the validity of the power reading will be in
question. For example, on the 2mA source range, the set low pulse (I-Low) level
must be 0nA ±600nA.
The Model 6221 will report the questionable power reading but will not generate
any front panel error messages. However, bit B4 (Power Questionable) of the
Questionable Event Status Register will set. For details, see
Structure.

Pulse Delta outputs

Pulse Delta output is made up of one or more Pulse Delta cycles. Each cycle is
made up of three output pulses (low, high, and low). The time period for a cycle is
adjustable and is the same for all cycles. The output pulses have an adjustable
pulse width, which is the same for all pulses.
There are two basic Pulse Delta output types: Fixed output and Sweep output. For
Fixed output, all high and low pulses are fixed for all Pulse Delta cycles in the test.
For Sweep output, the sweep (SWP) function of the Model is used to output a
staircased, logarithmic or user-specified (custom) pulse sweep.
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Pulse Delta voltage is 5V
Pulse high (I-High) current is 1mA
Pulse low (I-Low) current is 0mA
Duty cycle is 25%
= 1mA x 5V
= 5mW
= 1mA x 5V x 0.25
= 1.25mW
Return to
Delta, Pulse Delta, and Differential Conductance 5-35
Section 5 topics
Section 11, "Status