Delay Phase; Measurement Time - Keithley 2500 User Manual

Models 2500 and 2502 User's Manual
Figure 5-2
Simplified trigger model
Event
Event

Delay phase

The delay phase of the SDM cycle allows the source to settle before the measurement is
performed. The delay period depends on how the source delay is configured. The source
delay can be manually set from 0000.0000 seconds to 9999.9980 seconds. If using auto
delay, the delay is set automatically; see
The manually set delay (up to 9999.998 sec) is available to compensate for longer settling
required by external circuitry. The more capacitance seen at the output, the more settling
time is required for the voltage bias source. The actual delay period needed can be calcu-
lated or determined by trial and error. The slew rate of the output circuit is constant at
about 3.07ms/V. Therefore, the minimum source delay must be 3.07ms × voltage step
size.
NOTE

Measurement time

The measure time depends on the selected measurement speed. For example, if speed is
set at 0.01 PLC (power line cycles), the measure time would be 167µsec for 60Hz opera-
tion (0.01/60).
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com
Idle
Arm
Trig
Layer
Arm
Trigger
Trig
Layer
S D M
The delay period is the same for both channels. If you change the delay on one
channel, the delay period on the other channel will change to the same value.
Measurement Concepts
Source Delay Measure
See Section 10
for trigger model details.
Section 3 for details.
5-3