Keithley 2302, Instruction Manual, Page: 89 / 348

Pulse Current Measurements 3-27
For the active steps, the trigger level may be set to a value appropriate for each rising or falling
step, or set to the same value for all active steps. If using the same values for all TLEVx steps,
make sure the TLEV value set is appropriate for the smallest step (in
Figure 3-8 , the TLEV value
could not be greater than 275mA). See Table 3-5 for sample trigger level values.
Table 3-5
Sample TLEV values for Figure 3-8
TLEV x Unique TLEV x value Same TLEV x value
TELV1 550mA 200mA
TELV2 325mA 200mA
TELV3 200mA 200mA
TELV4 300mA 200mA
TELV5 500mA 200mA
TELV6 800mA 200mA
Use the one-shot method for measuring the pulses since this pulse sequence rises and falls
between steps. To accomplish this, configure the Model 2306 for measuring the pulse sequence
then generate the pulse sequence. (See the programming example
"One-shot pulse" on
page 3-33 ).
Pulse sequences — down steps first
Consider the pulse form in Figure 3-9 . This pulse form has three DOWN steps followed by
three UP steps but does not rise or fall between the steps.
Figure 3-9
TLEV2
400mA
TLEV1
750mA
450mA
575mA
700mA
900mA
600mA
300mA
TLEV3
500mA
TLEV4
625mA
100mA
Pulse form with down steps first (600
μ
sec step duration)
To measure the up step values in this pulse sequence, set the value for UP steps to equal the
sum of actual UP steps plus one while setting the DOWN step value to zero. In Figure 3-9 , the
UP steps are set to 4 and DOWN steps to 0. (If UP steps are set to a non-zero value, the
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