Interesting chip...

[David Halliday (Volt Computer)]

No, it is not 64 steps, the 64 comes from the fact that if you run the clock
from the crystal, you can tune it to one of 64 cutoff frequencies with just
a 6-bit control word.

There is no mention of how many steps the actual filter part is but it is a
7th order which is not too shabby!  Check out the specs.


-----Original Message-----
From: Mikko Helin [mailto:MHELIN at tne01.ntc.nokia.com]
Sent: Friday, October 09, 1998 2:15 AM
To: synth-diy at mailhost.bpa.nl
Cc: MHELIN at tne01.ntc.nokia.com
Subject: Re: Interesting chip...


This is a switched cap filter with only 64 steps, so it's not suitable
as a DCF. Could work as anti-aliasing filter after DCO (some uC like
PIC16F84 -> DAC -> s3528b).

-Mikko
>
>I was in Active Electronics earlier today getting some linear chips and
this
>package caught my eye:
>
>Programmable Low Pass Filter with 64X11Bit ROM for $4.95
>
>Hmmm...  Impulse purchase.  :-)
>
>The data can be found at:   
>http://www.amis.com/pdf/s3528b.pdf
>
>
>It is a nice 7th order Elliptical Ladder filter.  There are uncomitted
input
>and output opamps that can be used for whatever you want.  The frequency is
>either set by a six-bit control word ( ranges from 44 to 3891 Hz ) when
used
>with a 3.58MHz TV crystal or it can be set from 10Hz to 20KHz by externally
>clocking it with a TTL or CMOS clock signal.
>
>Just the thing for a crossover or filter bank element...
>
>
>Dave Halliday	( Cc... MSPAGE )
>B2/2132  /  2121	office  /  lab
>x20161	voice
>