Keithley 6220 Reference Manual page 161

Model 6220/6221 Reference Manual Delta, Pulse Delta, and Differential Conductance 5-41
Interval
The Pulse Delta cycle time period (interval) is expressed as a number of power
line cycles (PLC). For 60Hz, one PLC is 16.667ms, and for 50Hz, one PLC is
20ms. Interval can be set from 5 PLC (default setting) to 999999 PLC.
Sweep
The sweep function of the Model 6221 can be enabled (YES) or disabled (NO).
When disabled (which is the default setting), the Model 6221 will be configured to
output a fixed output using the programmed high and low pulse levels. When the
sweep function is enabled, the Model 6221 will be set to output a configured
sweep.
Low Measure
By default, three measurements are performed for every Pulse Delta interval. The
Model 2182A measures the voltage at pulse low, pulse high, and pulse low as
shown in Figure 5-9. As explained in the process for "Pulse Delta measurements,"
on page 5-32, a 2-point measurement technique can instead be used when pulse
high may cause DUT heating. For the 2-point measurement technique, the voltage
measurement for the second low pulse is not performed.
Sweep output settings
The following settings from the CONFIG PULSE DELTA menu (previously
described) are used for pulse sweep output: Width, Sweep, and Low Measure.
The sweep is selected and configured from the CONFIGURE SWEEPS menu that
is accessed by pressing the CONFIG key and then the SWP key. Details on
sweeps are provided in Section 4.
It is from the CONFIGURE SWEEPS menu that Source Ranging, Count, and
Sweep Delay are set:
Source Ranging
Source range can be set to BEST (default setting), FIXED, or AUTO. The BEST
and FIXED settings are described in "Sweep output settings". The AUTO setting is
available for a Sweep output. With AUTO selected, the instrument automatically
selects the optimum (lowest) range for the sweep step.
Delay
Sweep delay defines the Pulse Delta cycle time period (in seconds). The time
period is the same for all Pulse Delta cycles. Sweep delay can be set from 1ms to
999999.999s.
Return to Section 5 topics
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