Legato link dac chip,It reads data?

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Hello -

Pinout for the PD2029A is as follows:

1 - S/P
2 - RZ
3 - XTEST
4 - VDA
5 - RO
6 - XRO
7 - GNDA
8 - GNDA
9 - XLO
10 - LO
11 - VDA
12 - GNDX
13 - X1
14 - X0
15 - VDX
16 - GND
17 - C (H384Fs)
18 - LZ
19 - MCK
20 - LATCH
21 - SHIFT
22 - ATT
23 - NC
24 - XRESET
25 - DATA
26 - BCK
27 - LRCK
28 - VDD

Hope this helps,
Charles Hansen
 
Hi Charles,

Thanks
for the help!!!!


So

pin 5 = right channel non inv out?

6= right inv out

9 = left inv out

10 = left non inv out

Perhaps the wrong way round, but I suppose I can resolder to other pins if it sounds wrong, or even swap wires at the transformer instead if it sounds 'wrong'?

Thanks
Raja
 
Hello -

It may be hard to use this without more information, but you can try.

It's apparently a voltage output differential DAC. The RO and LO are the + outputs and the XRO and XLO are the - outputs.

When C is tied high, use a 384 Fs crystal at XI and XO. The MCK is unused in the circuit diagram I have (for a Pioneer DV-505 DVD player). TEST is not connected, while S/P is tied low. The whole thing runs off of 5 volts.

The LZ and RZ outputs are used to mute the analog circuits when there is no audio signal. This is a cheesy trick that all the Japanese companies use to get a better S/N ratio on the test bench, but in no way reflects the real world performance. You can ignore these outputs.

But the real problem is programming the thing. There is a 3 wire programming intreface. This is how you tell it the word length and format of the incoming signal, if de-emphasis should be applied, if you want to attenuate the signal, et cetera.

Without having the full data sheet, you'll have to rely on the default settings, whatever they may be. Typically it will be 16 bits right justified MSB first.

But why go through all this headache when you can by a nice DAC chip for $5 or less that will have a data sheet?

Good luck,
Charles Hansen
 
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