"Jim Lesurf" wrote in message

In article ,
John Phillips wrote:
On 2006-10-30, Jim Lesurf
wrote:
[snip]

Hence the original Philips 14-bit x4 oversampling
system would be able, in principle, to deliver full
16-bit resolution *if* the chips and the associated
electronics was made with suitable care. As usual, the
practical limits end up being determined by the care
put into engineering the actual implimentation. :-)

I looked up the details of the chipset. It seems that
the SAA7030 does the interpolation and does a large part
of the reconstruction filtering. It has a 96-point FIR
filter at 4x input rate with a 28-bit accumulator
(16-bit data, 12-bit coefficients).

The thing that struck me from the datasheet is that the
28 bit accumulator seems to get truncated without dither
to 14 bits and then sent to the DAC (a TDA1540).

My (unreliable) recollection is that noise shaping is
employed, but (see below) I can't recall the details
off-hand.

I found the spec sheet for the TDA1540 and SAA 7030 online, and can confirm
that noise shaping is done in the SAA 7030.

The TDA 1540 spec sheet was found at the Signetics web site.

BTW the speced dynamic range of the TDA 1540 is 85 dB.