Appendix B: Algorithms
TDS 620A, 640A, & 644A User Manual
High
HighRef
LowRe
f
Lo
w
TL
F
THF
Fall
Time
Figure A-2: Fall Time
Frequency
Timing measurement. The reciprocal of the period. Measured in Hertz (Hz)
where 1 Hz = 1 cycle per second.
If = 0 or is otherwise bad, return an error.
= 1/
High
100% (highest) voltage reference value. (See “High, Low” earlier in this
section)
Using the min-max measurement technique:
=
Low
0% (lowest) voltage reference value calculated. (See “High, Low” earlier in
this section)
Using the min-max measurement technique:

=