Dir 1703 + Ad1865

[kkchunghk]

Hi,

There is a discussion on a Chinese forum that the DIR1703 and AD1865 do not match without shift logic. Since the AD1865 data format is right justified, if I select the 16-bit right justified format for the DIR 1703 to capture 16-bit SPDIF, then all the AD1865 sees is 2 bits of 0s before the MSB. It would seem to work without shift logic. Will it work?

K K

[nicoch58]

hi can you help?

I have usb module from dddac that output a i2s and cd denon dcd-2650 with 4 ad 1862 , I want transformer in a usb dac 1862!

is possible?

[kkchunghk]

Hi nicoch46,
If I understand you correctly, you want to change a 16-bit I2S signal to a 20-bit right justified one. I think this might help:

http://www.geocities.com/nonospcm17...al_shifter.html

In this case, the data will be right shifted by 11 bit so that the 1862 sees the the last 20th bit as the MSB. I have simulated the logic in Pspice but have not tried it for real.

So can you get the 2707 in dddac to work ? Lucky fella. My own circuit has not been successful. Of about one thousand times I plugged in the chip, I have only one positive response from the computer. Other times the computer always return the messasge - device not recognised. I don't know if others also find the chip hostile.

Having read another post I think I can answer my own question in post #1. I will set the 1703 in 16-bit right justified mode and shift the latch clock by 2 bits. Then the MSB will align.

Cheers,

KK