Mon Jul 30 19:53:05 EDT 2012


Paraphrasing Dan Piponi, sometimes you can learn more from trying to
decipher a single sentence in an advanced paper that's way over your
head, than from going through introductory or course material that is
intended to teach you things gradually.  I've seen this happen so many
times: it's wrong and confusing until suddenly it's right and clear.

For S/D I was reading this book[1] and it made me realize that a
switchcap filter is discrete in time but continous in amplitude, while
any other digital signal is both discrete in time and amplitude.

However, the Z-transform used in digital signal processing is actually
defined in terms of real number amplitudes which makes a switchcap
filter a better representative of a discrete filter than an ordinary
finite-precision digital filter!

One of those things that's obvious and fairly basic in retrospect but
hiding in a corner until it was made explicit..

[1] isbn://0792393090
[2] http://en.wikipedia.org/wiki/Switched_capacitor