In Reply to: RE: Jitter posted by Jaundiced Ear on June 2, 2012 at 17:11:05:
Sorry, the definition of jitter is fairly simple, but the causes can be much more complicated to explain. Note that there is jitter always present that is somewhat analogous to the wow and flutter example, and most people may not be bothered by it, or even recognize its presence. It can be caused by ground loops, so you may have a power line frequency on the conversion clock that becomes a jitter component. Many digital components have very large amounts of low frequency jitter and users aren't bothered by it all that much. Clocks drift with temperature and power supply levels and are easily influenced by other digital and analog operations in the device (and even outside the device).
But the type of jitter I was describing as data-correlated is mostly caused by highly non-linear interactions between the data and clock while still in the digital domain, so doesn't really sound like something that happens naturally in the analog world. Maybe something like a distorted ghost of the music in the background, but also displaced in time. Music is repetitive by nature, and the repeating data bit patterns can be coupled to the conversion clock through a variety of means because the data waveform is not symmetric like a clock. Even a simple operation like transferring the data and clock from a digital filter output to the D/A convertor input can add data-correlated jitter to the clock since they share the same return, and the data bit pattern will modulate that return.
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Follow Ups
- RE: Jitter - slider 20:08:43 06/02/12 (0)