[Mahen K]

On Aug 16, 10:42*pm, Dick Pierce wrote:
Mahen K wrote:
Hi,

Digital Audio receiver ICs like DIR9001 and CS8414 mention the diff
voltage level at their input pins RXP and RXN as 200mv min while the
Digital Audio Transsmitters like DIT4096 and CS8406 use *5V logic
levels. How are they compatible with wide difference in levels? I am
looking at using them for SPDIF transmission and reception.

*From IEC 958 5.3.3.3 "Minimum input signals",

* * Minimum input voltage shall be 0.2V peak-to-peak

That is, the MINIMUM input voltage.

Now, if you actually read the specs for, oh, the DIT4096,
you might discover that even though the "core voltage" is
5 volts, a figure more relevant to your issues is the
"high-level output voltage Voh" which is listed at 0.8V

Further inspection of the spec sheet reveals, in figure
11, a block referred to as the "output circuit," which
is elucidated in figures 12, 13 and 14. FIgure 13 is,
again, most relevant to your question. It shows the
output circuit for a SP/DIF circuit, consisting,
significantly of a 2:1 step-down pulse transformer,
which would make it completely compatible with the
IEC 958 standard.

Aren't spec sheets wonderful?

--
+--------------------------------+
+ * * * * Dick Pierce * * * * * *|
+ Professional Audio Development |
+--------------------------------+

Thanks for quick response. I couldn't find Voh as 0.8V anywhere in
the DIT4096 datasheet. The datasheet in page 3 says Voh for TX+ and
TX- is "Vdd - 0.4v" typical which translates to 4.6v. With 4.6V and
2:1 step down transformer, is o/p compatible with consumer spdif
inputs? I just chekced the levels for RX1+ and RX1- inputs of SRC4392
in the datasheet and it is max 200mv which is not compatible with the
above scheme unless I am missing something.

-mjnk