[sdiy] Digital Noise, FYI

[Scott Gravenhorst]

Matthew Smith <matt at smiffytech.com> wrote:
>Quoth David G. Dixon at 16/02/11 17:31...
>...
>>> 555 -> CPLD -> 10-bit parallel load DAC
>
>I actually got that a bit wrong - it's a 12-bit DAC, the MX7541, which 
>is just a Mexican version of the AD7541 ;-) (Not really, it's the Maxim 
>version. Just my silly joke.)
>
>> That's an awesome circuit, from an awesome book.  It's high on my to-do list
>> as well.
>
>I'd recommend Lancaster's books to anyone in this field - he's a really 
>good teacher, it's just a shame he never published more. I have the TTL 
>Cookbook, CMOS Cookbook, Active Filter Cookbook.
>
>To address Dave Manley's question, yes. String of flipflops with some 
>XOR gates. (Photo of relevant page mailed to Dave.)

For anyone interested, here is a table of taps for maximal length LFSR pseudorandom number
generation (or noise):

http://home1.gte.net/res0658s/electronics/LFSRtaps.html

The list includes LFSR lengths from 3 bits to 168 bits.  The more taps, the better.  I
typically use 64.

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
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