In Reply to: Re: Hi Ted. what you do??edit a typo? posted by jneutron on August 23, 2003 at 10:28:39:
HowdyOf course a reconstruction filter produce outputs higher than the input, otherwise how could they reproduce the original waveform without waiting for a peak :) A reconstruction filter isn't just a smoothing filter. Anyway ever hear of filters ringing? If you hit a reconstruction filter with a single non-zero sample, you'll not only get an output of some amplitude at that point but also non-zero outputs at other points, when there are more than one sample those other "spurious" outputs can overlap constructively or destructively and cause the output at any given point to be higher or lower than you might otherwise expect.
The reconstruction filter is a part of the DAC.
To do a proper brickwall filter it must look into the future a little, (by delaying the output a little) but that has it's own problems...
There is no such thing as an ideal implementation of a reconstruction filter, but in any case the better the filter, the better it's time resolution... which is what brought the whole thing up in the first place.
-Ted
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: Hi Ted. what you do??edit a typo? - Ted Smith 11:25:20 08/23/03 (4)
- What's confusing to most people about this - Commuteman 17:37:13 08/23/03 (2)
- Re: What's confusing to most people about this - Ted Smith 19:13:42 08/23/03 (1)
- Re: What's confusing to most people about this - jneutron 07:47:01 08/25/03 (0)
- Re: Hi Ted. what you do??edit a typo? - john curl 13:20:02 08/23/03 (0)