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Deeper Understanding of the Difference Between Digital Oscilloscopes and Analog Oscilloscopes

What is the difference between a digital oscilloscope and an analog oscilloscope?

An oscilloscope is an indispensable tool for engineers and technicians in observing and analyzing electronic waveforms. Did you know that the initial oscilloscopes only allowed for observing voltage changes over time to provide qualitative assessments? Surprising, right? So, how has the oscilloscope evolved with technological advancements? Let's explore the differences between digital and analog oscilloscopes with Trung Kiên Techdevinco!

Analog Oscilloscope

First, let's talk about analog oscilloscopes. Known for their real-time display capability, analog oscilloscopes use vertical amplifiers and cathode ray tubes (CRT) to display signals. Engineers often use this type of oscilloscope to directly observe waveforms and make quick adjustments. A prominent strength of analog oscilloscopes is their ability to update waveforms very quickly, up to over 100,000 sweeps per second at high sweep rates. This allows for the immediate display of any changes in the signal.

However, analog oscilloscopes also have their limitations. For instance, as the signal frequency increases, the process requirements of the CRT become stringent and costs rise. This makes it difficult to expand the bandwidth of analog oscilloscopes without encountering technological bottlenecks.

Digital Oscilloscope

Digital Oscilloscope

To overcome the limitations of analog oscilloscopes, digital oscilloscopes (DSO) were developed. In the 1980s, digital processing and microprocessors were integrated into oscilloscopes, leading to a significant breakthrough. DSOs use A/D converters to sample signals and memory to store data, allowing for automatic measurements and more precise signal analysis.

What’s special about DSOs is their ability to process and store waveform data. DSOs can record random events, capture burrs, process waveforms, and even output hard copies of waveforms. You can imagine that with a DSO, analyzing signals becomes much easier. However, DSOs also have drawbacks, such as a lower waveform update rate compared to analog oscilloscopes, which can cause a delay between the change in the signal and its display on the screen.

Detailed Comparison

1. Frequency and Bandwidth

Analog oscilloscopes rely on amplifiers and CRTs to handle bandwidth, leading to high costs as the frequency increases. In contrast, DSOs use high-speed A/D converters and other low-speed components, reducing costs and overcoming the limitations of CRTs. The bandwidth of a DSO depends on the sampling rate, which is typically four times the bandwidth.

2. Functionality and Performance

DSOs have many advanced functions such as enhanced triggers, burr capture, and waveform processing that analog oscilloscopes do not possess. However, analog oscilloscopes excel in real-time display capabilities with high waveform update rates, instantly showing any changes in the signal.

3. Resolution and Storage

Typical DSOs have 8-bit vertical resolution, requiring large memory to store signals. The storage capacity of DSOs affects the sweep rate and waveform processing capabilities. In contrast, analog oscilloscopes do not face this issue but may struggle to display low-frequency signals due to the short afterglow time of CRTs.

4. Signal Display Differences

Analog oscilloscopes display the input voltage signal immediately, providing accurate real-time observation. On the other hand, DSOs display waveforms reconstructed from sampled data, which can introduce display delays.

5. Complex Repeating Signals

For complex repeating signals like TV signals, DSOs may struggle to show waveform details due to limited sampling points. Analog oscilloscopes, with their detailed display capabilities, provide better analysis of different signal components.


Each type of oscilloscope has its own advantages and limitations, suited to different needs and technical requirements. Analog oscilloscopes offer excellent real-time display capabilities, while DSOs provide advanced functions and better waveform data storage. Choosing the right oscilloscope depends on specific job requirements and usage environments.

Trung Kiên Techdevinco is always ready to provide advanced technological solutions to meet all customer needs. Don’t hesitate to contact us through our website at for the best advice and support!


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