The difference between analog oscilloscopes and digital oscilloscopes on simple repetitive signals

An oscilloscope is a widely used electronic measuring instrument that can transform invisible electrical signals into visible images, making it easier for people to study the changing processes of various electrical phenomena. Oscilloscopes can be divided into analog oscilloscopes and digital oscilloscopes. The following is a description of the differences between analog oscilloscopes and digital oscilloscopes in simple repetitive signals.

Simple repetitive signals are usually well viewed using both analog oscilloscopes and DSOs. However, both have their advantages and limitations. For analog oscilloscopes, it is difficult to display very low frequency signals because the afterglow time of the CRT is very short. Since the brightness of the trace on the oscilloscope is inversely proportional to the sweep speed, low repetition rate signals with fast rise and fall times are difficult to see. The brightness and sweep speed of the DSO trace are independent of the signal repetition rate. Depending on the signal being measured, this feature can be an advantage or a disadvantage.

For displaying fast edges of repetitive signals with sufficiently high repetition rates, there is little difference in performance between DOS and analog oscilloscopes. Both oscilloscopes can provide good visualization of signal waveforms.

When measuring signal parameters, the advantage of DSO is that it has the ability to measure automatically. When using an analog oscilloscope, the user must set the cursor and analyze and understand the displayed waveform to obtain the measurement result.

If you need to make adjustments, it is usually best to use an analog oscilloscope. This is because the real-time display capability of an analog oscilloscope allows it to display the input voltage at every moment. Its waveform update rate is very high, and can exceed 100,000 scans/second at high scan speeds. Therefore, any changes in the signal will be displayed immediately. Moreover, some changes in the signal will be shown on the display screen in the form of changes in the brightness of the waveform.

Contrary to analog oscilloscopes, DSOs display waveforms reconstructed from acquired waveform data. The number of waveform flashes acquired per second is far less than 100. On some oscilloscopes, the number of waveform flashes acquired per second is more than 5. As a result, there is a significant time delay between the signal changing and the changed signal being displayed on the screen. This is a major disadvantage of using a DSO when making adjustments to the system.