From: Farhad Abdolian
Subject: Re: Looking for PWM controller with SPI interface
X-Newsreader: Forte Agent 1.8/32.548
Date: Mon, 23 Sep 2002 20:59:43 GMT
NNTP-Posting-Date: Mon, 23 Sep 2002 16:59:43 EDT
Organization: Road Runner - NYC
Since you are thinking about using some standard logic chips to do the job, I
would recomend another solution, use some cheap CPLDs, you can buy them in small
quantities from Xilinx and they cost less than $10 each for a 72 macrocell 9572,
they are in circuit programmable and you can use schematic capture to do your
design, this gives you a lot of benefits compare to TTL, your design will be
smaller (one chip instead of a dusin), it makes it easier to modify in case you
find problem with your design or want to add functionality to it and best of all
the time you spend on learning the CPLD programming is something that you can
use in all you projects in the future!
Or if you just want to make a couple of them and do not want the hassle of
learning the tools, send me a copy of your schematic, and I make the conversion
and send you the JEDEC file for your CPLD (I like promoting programmable instead
of standard logic :)
Daniel Haude wrote:
>On Fri, 20 Sep 2002 18:07:05 GMT,
> Farhad Abdolian wrote
> in Msg.
>| The easiest way to do it is to use a small micro controller a PIC or Atmel 89
>| series, and make a software PWM inside of it. It is cheaper, faster, and it can
>| even give you more channels than any device you can find on the market, on the
>| other hand, you need to program it, which is more difficult than buying a chep
>| off the shelf.
>Right, that's why I explicitly ruled out the Microcontroller. I guess I'll just
>slap a few latched shift registers, a counter, and some magnitude comparaters
>together to do the trick. Aah, good old TTL. I guess a simple GAL would do it,
>too, but I can't program that either.