Digital storage oscilloscope

Digital storage oscilloscope
A Tektronix TDS210 digital oscilloscope

A digital storage oscilloscope is an oscilloscope which stores and analyses the signal digitally rather than using analogue techniques. It is now the most common type of oscilloscope in use because of the advanced trigger, storage, display and measurement features which they typically provide.[1]

The input analogue signal is sampled and then converted into a digital record of the amplitude of the signal at each sample time. The sampling frequency should be the Nyquist rate or better to avoid aliasing. These digital values are then turned back into an analogue signal for the display if this is a cathode ray tube (CRT) or otherwise transformed as needed for the various possible types of output — liquid crystal display, chart recorder, plotter or network interface.[2]

Digital storage oscilloscopes are usually large and expensive — $400 USD or more. However, small, pocket-size models are now available which, though limited in function, may retail for as little as $50 USD.[3]



Digital oscilloscopes will usually analyse and provide values as well as visual displays. These values will typically include averages, minima, maxima, root mean square (RMS) and frequencies. They may be used to capture transient signals when operated in a single sweep mode — something that was normally difficult to achieve with an analogue oscilloscope.[4]


  1. ^ Ian Hickman (1997), Digital storage oscilloscopes, Newnes, ISBN 9780750628563, 
  2. ^ Hughes electrical and electronic technology, Pearson Education, 2008, p. 953, ISBN 9780132060110 
  3. ^ Charlie Sorrel (May 13, 2009), "DIY Oscilloscope is Awesomely Affordable", Wired, 
  4. ^ Alan S. Morris (2001), Measurement and instrumentation principles, Butterworth-Heinemann, p. 211, ISBN 9780750650816 

Further reading

External links

Resources (White papers, technical papers, application notes)