PeakTech 2035 Bedienungsanleitung Seite 53

To measure rise and fall time, proceed as follows:
1. Connect the pulse to be measured to the CH 1-IN connector (24), and set the AC/GND/DC switch
(25) to AC.
2. Adjust the TIME/DIV switch (15) to display about 2 cycles of the pulse. Make certain the VAR
switch (12) is rotated fully clockwise.
3. Center the pulse vertically with the cannel 1 Vertical Position control (4).
4. Adjust the channel 1 VOLTS/DIV switch (26) to make the positive pulse peak exceed the 100 %
gratitude line, and the negative pulse peak exceed the 0 % line, then rotate the VARIABLE
control (27) counterclockwise until the positive and negative pulse peeks rest exactly on the 100
% and 0 % gratitude lines (See Figure 2.12).
5. Use the Horizontal POSITION control (10) to shift the trace so the leading edge passes through
the intersection of the 10 % and central vertical gratitude lines.
6. If the risetime is slow compared to the period, no further control manipulations are necessary. If
the risetime is fast (leading edge almost vertical), to set x10 MAG to the X10 MAG position and
reposition the trace as in Step 5 (See Figure 2-10 b).
7. Count the number of horizontal divisions between the central vertical line (10 % point) and the
intersection of the trace with the 90 % line.
8. Multiply the number of divisions counted in step 7 by the setting of the TIME/DIV switch to find
the measured risetime. If 10 x magnification was used, divide the TIME/DIV setting by 10. For
example, if the timebase setting in Figure 2-10 was 1 s/div (1000 ns), the risetime would be 360
nanoseconds
(1000 ns ÷ 10 = 100 ns, 100 ns x 3.6 div = 360 ns)
9. To measure falltime, simply shift the trace horizontally until a trailing edge passes through the 10
% and central vertical gratitude lines, and repeat Steps 7 and 8.
10. When measuring the rise and fall time, note that 17.5 ns-Rise time (tr) = 0.35/f-3dB which
is transition time is contained in the PeakTech 2020 GN oneself. Therefore the real
transition time (tc) is composed of
all is explained with the following formula:
tc = √ tm² - tr²
a) Basic Display Setup
tc = Real transition time
tm = Measured transition time
tr = Rise time of oscilloscope
Figure 2-12: Risetime Measurement
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measure transistion time (tm) and tr. The above
b) With horizontal Magnification