Sampling oscilloscope: Difference between revisions

From TekWiki
Jump to navigation Jump to search
No edit summary
No edit summary
Line 3: Line 3:


A distinction is made between real-time and equivalent time sampling. Real-time sampling requires a sampling rate of at least twice the highest signal bandwidth to capture the signal without artifacts. It is rare with analog oscilloscopes, but the method of choice for low to medium speed digital oscilloscopes, and allows for single shot waveform aquisition.
A distinction is made between real-time and equivalent time sampling. Real-time sampling requires a sampling rate of at least twice the highest signal bandwidth to capture the signal without artifacts. It is rare with analog oscilloscopes, but the method of choice for low to medium speed digital oscilloscopes, and allows for single shot waveform aquisition.
:{|
|-
| [[File:RealTimeSampling_Fig29_XYZs_of_Oscill.png|500px]] || [[File:EquivTimeSampling_Fig32_XYZs_of_Oscill.png|400px]]
|-
| style="text-align:center;"|Real-Time Sampling      || style="text-align:center;"|Equivalent Time Sampling
|-
|}


Equivalent time sampling requires repetitive signals but allows to capture a fast signal with a sampling rate much slower than the signal bandwidth. It is further divided into sequential, and [[random sampling]].
Equivalent time sampling requires repetitive signals but allows to capture a fast signal with a sampling rate much slower than the signal bandwidth. It is further divided into sequential, and [[random sampling]].
Instruments that have a random sampling mode usually also have a sequential sampling mode, e.g., the [[7T11]].
Instruments that have a random sampling mode usually also have a sequential sampling mode, e.g., the [[7T11]].
:{| style="width: 60%;"
|-
| [[File:RandomTimeSampling_Fig33_XYZs_of_Oscill.png|600px]] || [[File:SequentialTimeSampling_Fig34_XYZs_of_Oscill.png|600px]]
|-
| style="text-align:center;"|In random equivalent-time sampling, the sampling clock runs asynchronously with the input signal and the trigger.      || style="text-align:center;"|In sequential equivalent-time sampling, the single sample is taken for each recognized trigger after a time delay which is incremented after each cycle.
|-
|}


== Scopes ==
== Scopes ==

Revision as of 09:55, 4 June 2022

Tektronix made oscilloscopes and plug-ins intended for sampling measurements. Through the 1960s, the sampling group was led by Al Zimmerman.

A distinction is made between real-time and equivalent time sampling. Real-time sampling requires a sampling rate of at least twice the highest signal bandwidth to capture the signal without artifacts. It is rare with analog oscilloscopes, but the method of choice for low to medium speed digital oscilloscopes, and allows for single shot waveform aquisition.

Real-Time Sampling Equivalent Time Sampling


Equivalent time sampling requires repetitive signals but allows to capture a fast signal with a sampling rate much slower than the signal bandwidth. It is further divided into sequential, and random sampling. Instruments that have a random sampling mode usually also have a sequential sampling mode, e.g., the 7T11.

In random equivalent-time sampling, the sampling clock runs asynchronously with the input signal and the trigger. In sequential equivalent-time sampling, the single sample is taken for each recognized trigger after a time delay which is incremented after each cycle.

Scopes

Plug-ins

Reading