SV: Re: [sdiy] 16bit DC, DAC, SPI!

[Eric Brombaugh]

karl dalen wrote:
 > --- Eric Brombaugh <ebrombaugh at earthlink.net> skrev:
 >
 >> ...And if I'd been reading the Subject: line more carefully I would 
have realized that this wasn't what you wanted.
 >>
 >> Sorry for the noise. I'll go stand in the corner now...
 >>
 >> Eric
 >
 > I found the mail:
 >
 > The thing is im using a PCM56 and i suspect its going EOL.
 > Old as my grannie but net since its rellay fast and infact it was
 > cheap untill recently TI more then doubbled its price and that may be 
a a sign something is about to happend with the device.
 > Anyhow does sigma delta ripple at DC by default/design?

Yup - I'm kind of a one-trick pony. :)

Sigma-Delta does ripple at the sample rate, but I don't believe the DC 
ripple would be any worse than the overall SNR so I'd guess it's going 
to be down 90dB or so. Considering peak-peak swing on these is about 3V, 
figure 100 microvolts ripple? You've probably got more than that in 
ordinary digital noise.

Eric