[mythtv-users] Heat issues with USB ATSC tuners?

[Devin Heitmueller]

On Thu, Aug 30, 2012 at 3:48 PM, rsh1k <roland.sh1000 at gmail.com> wrote:
> Ahh, it seems as though you are correct.  I must have been thinking of
> a different model.
>
> Either way, the 950q has the whole set of analog audio/video
> circuitry...  which might be much lower power without an encoder, but
> it still takes *some* power to run.

The analog video decoder block of the au8522 is powered down when
doing digital capture.  The device actually exceeds the 500ma limits
if both the digital and analog sides of the board are powered up in
parallel (which is why I wrote the driver to prevent it from ever
entering this state).

For what it's worth, it's not really drawing 500ma (that's the limit).
 If I recall in digital mode it's more in the 300-350 range.  All that
said, this is a typical draw compared to other devices - tuning and
VSB or QAM demodulation of 19.2 Mb/s or 38 Mb/s worth of data is just
something that consumes power.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com