Math
93
9.3 Math Function Operation
The oscilloscope supports math function operation including differential (d/dt), integral (
∫ 𝑑𝑡
) and square root (
√
).
9.3.1 Differentiate
𝑑𝑖 =
𝑦(𝑖 + Δ𝑡) − 𝑦(𝑖 − Δ𝑡)
2Δ𝑡
d/dt
(differentiate) calculates the discrete time derivative of the selected source. Where:
• d = differential waveform
• y = channel 1, 2, 3, or 4 data points
• i = data point index
• Δ t = point- to- point time difference
The
dx
option under d/dt math function operation menu shows the point- to- point time difference, and it ranges from
0.02div to 0.40div. “div” indicates the number of the pixel points that each division has. The oscilloscope has 50 pixel
points per division. Take 0.2div as an example: 0.2*50 = 10. It means to calculate the ten point’s discrete time derivative
of the selected source, and the Δ t is the ten point’s point-to-point time difference.
Figure 9.12
Difference Function Operation
You can use differentiate to measure the instantaneous slope of a waveform. For example, the slew rate of an operational
amplifier may be measured using the differentiate function
Note:
Because differentiation is very sensitive to noise, it is helpful to set acquisition mode to Average.
