what's the best way to convert SPDIF into CMOS level?

[banana]

Hello all,

I'm working with DIR1701 as receiver. However, it's D_in only accept CMOS level, I need to convert SPIDF signal into CMOS level.

TI (on DEM-DIR1701 instruction manual) suggest using a two stage 74HCU04 buffer to do the level convert. Is there a better way to do it? Or are there any "low jitter" gates for building the buffer??



Thanks in advance.

[Guido Tent]

Hi,

Treat SPDIF as it where analog. I'd suggest a decent opamp like AD811, with 5 times gain or so.

regards

[till]

thread "CS8412 or AD1892?"
posting#41

[banana]

Thanks Gudio and Till.

ADM1485 looks like a good fit. But I have no idea how it would compare to 74CU04, in terms of clock skew.

And about using Opamp..... How do I ensure the Opamp's output is 0~5V? Does it mean running the Opamp with +5V single supply?

[andrei]

Use a specialized RS-485 receiver, like LTC1685 (or ADM1485).

[Guido Tent]

Originally posted by andrei
Use a specialized RS-485 receiver, like LTC1685 (or ADM1485).

be careful, they all sound different !

Guido

[Bricolo]

Guido, why a gain of 5 for the opamp?

Isn't SPDIF 0-0.5V and CMOS 0-5V? So a gain of 10 would be required.

[till]

"be careful, they all sound different !"

yea, and don´t forget the stone on your transport.

[carlosfm]

Originally posted by Guido Tent
Hi,

Treat SPDIF as it where analog. I'd suggest a decent opamp like AD811, with 5 times gain or so.

regards

What about the LM6171? or ?

5 times gain?
Shouldn't it be 10x?

[Guido Tent]

Originally posted by Bricolo
Guido, why a gain of 5 for the opamp?

Isn't SPDIF 0-0.5V and CMOS 0-5V? So a gain of 10 would be required.

Yes, in theory, but I like to reduce the amplitude in order to reducce the RF current entering the receiving. A tradeof between slope and amplitude

You can play around with it, ofcourse

regards