Recent from talks
Oscilloscope types
Knowledge base stats:
Talk channels stats:
Members stats:
Oscilloscope types
This is a subdivision of the Oscilloscope article, discussing the various types and models of oscilloscopes in greater detail.
While analog devices make use of continually varying voltages, digital devices employ binary numbers which correspond to samples of the voltage. In the case of digital oscilloscopes, an analog-to-digital converter (ADC) is used to change the measured voltages into digital information. Waveforms are taken as a series of samples. The samples are stored, accumulating until enough are taken in order to describe the waveform, which are then reassembled for display. Digital technology allows the information to be displayed with brightness, clarity, and stability. There are, however, limitations as with the performance of any oscilloscope. The highest frequency at which the oscilloscope can operate is determined by the analog bandwidth of the front-end components of the instrument and the sampling rate.
Digital oscilloscopes can be classified into two primary categories: digital storage oscilloscopes and digital sampling oscilloscopes. Newer variants include PC-based oscilloscopes (which attach to a PC for data processing and display) and mixed-signal oscilloscopes (which employ other functions in addition to voltage measurement).
The digital storage oscilloscope, or DSO for short, is now the preferred type for most industrial applications. Instead of storage-type cathode ray tubes, DSOs use digital memory, which can store data as long as required without degradation. A digital storage oscilloscope also allows complex processing of the signal by high-speed digital signal processing circuits.
The vertical input is digitized by an analog-to-digital converter to create a data set that is stored in the memory of a microprocessor. The data set is processed and then sent to the display, which in early DSOs was a cathode ray tube, but today is an LCD flat panel. DSOs with color LCDs are common. The sampling data set can be stored to internal or removable storage or sent over a LAN or USB for processing or archiving. A screen image can also be saved to internal or removable storage, or sent to a built-in or externally connected printer, without the need for an oscilloscope camera. The oscilloscope's own signal analysis software can extract many useful time-domain features (e.g., rise time, pulse width, amplitude), frequency spectra, histograms and statistics, persistence maps, and a large number of parameters meaningful to engineers in specialized fields such as telecommunications, disk drive analysis and power electronics..
Digital oscilloscopes are limited principally by the performance of the analog input circuitry, the duration of the sample window, and resolution of the sample rate. When not using equivalent-time sampling, the sampling frequency should be higher than the Nyquist rate which is double the frequency of the highest-frequency component of the observed signal, otherwise aliasing occurs.
Advantages over the analog oscilloscope are:
A disadvantage of older digital oscilloscopes is the limited waveform update rate (trigger rate) compared to their analog predecessors, which can make it difficult to spot "glitches" or other rare phenomena with digital oscilloscopes, especially older ones that have no persistence mode. However, thanks to improvements in waveform processing, newer digital oscilloscopes can reach trigger rates in excess of 1 million updates/second, which is more than the roughly 600,000 triggers/sec the best analog oscilloscopes were able to do. Newer digital oscilloscopes also come with analog persistence modes, which replicate the afterglow of an analog oscilloscope's phosphor CRT.
Hub AI
Oscilloscope types AI simulator
(@Oscilloscope types_simulator)
Oscilloscope types
This is a subdivision of the Oscilloscope article, discussing the various types and models of oscilloscopes in greater detail.
While analog devices make use of continually varying voltages, digital devices employ binary numbers which correspond to samples of the voltage. In the case of digital oscilloscopes, an analog-to-digital converter (ADC) is used to change the measured voltages into digital information. Waveforms are taken as a series of samples. The samples are stored, accumulating until enough are taken in order to describe the waveform, which are then reassembled for display. Digital technology allows the information to be displayed with brightness, clarity, and stability. There are, however, limitations as with the performance of any oscilloscope. The highest frequency at which the oscilloscope can operate is determined by the analog bandwidth of the front-end components of the instrument and the sampling rate.
Digital oscilloscopes can be classified into two primary categories: digital storage oscilloscopes and digital sampling oscilloscopes. Newer variants include PC-based oscilloscopes (which attach to a PC for data processing and display) and mixed-signal oscilloscopes (which employ other functions in addition to voltage measurement).
The digital storage oscilloscope, or DSO for short, is now the preferred type for most industrial applications. Instead of storage-type cathode ray tubes, DSOs use digital memory, which can store data as long as required without degradation. A digital storage oscilloscope also allows complex processing of the signal by high-speed digital signal processing circuits.
The vertical input is digitized by an analog-to-digital converter to create a data set that is stored in the memory of a microprocessor. The data set is processed and then sent to the display, which in early DSOs was a cathode ray tube, but today is an LCD flat panel. DSOs with color LCDs are common. The sampling data set can be stored to internal or removable storage or sent over a LAN or USB for processing or archiving. A screen image can also be saved to internal or removable storage, or sent to a built-in or externally connected printer, without the need for an oscilloscope camera. The oscilloscope's own signal analysis software can extract many useful time-domain features (e.g., rise time, pulse width, amplitude), frequency spectra, histograms and statistics, persistence maps, and a large number of parameters meaningful to engineers in specialized fields such as telecommunications, disk drive analysis and power electronics..
Digital oscilloscopes are limited principally by the performance of the analog input circuitry, the duration of the sample window, and resolution of the sample rate. When not using equivalent-time sampling, the sampling frequency should be higher than the Nyquist rate which is double the frequency of the highest-frequency component of the observed signal, otherwise aliasing occurs.
Advantages over the analog oscilloscope are:
A disadvantage of older digital oscilloscopes is the limited waveform update rate (trigger rate) compared to their analog predecessors, which can make it difficult to spot "glitches" or other rare phenomena with digital oscilloscopes, especially older ones that have no persistence mode. However, thanks to improvements in waveform processing, newer digital oscilloscopes can reach trigger rates in excess of 1 million updates/second, which is more than the roughly 600,000 triggers/sec the best analog oscilloscopes were able to do. Newer digital oscilloscopes also come with analog persistence modes, which replicate the afterglow of an analog oscilloscope's phosphor CRT.