Differential Output

A

Apparatus

Guest
Hello,

I am using a Texas Instruments TLV320AIC1106 PCM Codec for some audio
circuitry. This codec is capable of driving an 8 to 32 ohm load
speaker. The suggested connection topology for this speaker is
differential output according to the datasheet, but a schematic is not
included with this recommendation.

I was planning to simply connect one terminal of the speaker to EAROUT+
and the other to EAROUT-, but recently it was suggested to me that in
addition I couple each terminal to ground with a 1kohm resistor. What
are the advantages of this?

Cheers,
Chris
 
Apparatus wrote:
Hello,

I am using a Texas Instruments TLV320AIC1106 PCM Codec for some audio
circuitry. This codec is capable of driving an 8 to 32 ohm load
speaker. The suggested connection topology for this speaker is
differential output according to the datasheet, but a schematic is not
included with this recommendation.

I was planning to simply connect one terminal of the speaker to EAROUT+
and the other to EAROUT-, but recently it was suggested to me that in
addition I couple each terminal to ground with a 1kohm resistor. What
are the advantages of this?

Cheers,
Chris
Click to expand...
None.
 
Thank you all for your informative answers. The speaker is
disconnectable (headphones via phonojack), but the initial center point
offset should only induce a click or pop sound in the headphones. Since
this is not a problem, I'll leave out the resistors.

Cheers,
Chris
 
Apparatus wrote...
Thank you all for your informative answers. The speaker is
disconnectable (headphones via phonojack), but the initial
center point offset should only induce a click or pop sound
in the headphones. Since this is not a problem, I'll leave
out the resistors.
Click to expand...
I don't understand your comment about center-point offset.
In these balanced amplifiers, both outputs are at the same
voltage with no signal, so the difference voltage is zero,
and plugging in a headphone should not make a click. Note,
the outer ring of the headphone jack shouldn't be grounded!


--
Thanks,
- Win
 
I read in sci.electronics.design that Winfield Hill <hill_a@t_rowland-
dotties-harvard-dot.s-edu> wrote (in <cpi6gb073g@drn.newsguy.com>) about
'Differential Output', on Sun, 12 Dec 2004:
I don't understand your comment about center-point offset.
In these balanced amplifiers, both outputs are at the same
voltage with no signal, so the difference voltage is zero,
and plugging in a headphone should not make a click. Note,
the outer ring of the headphone jack shouldn't be grounded!
Click to expand...
Well, theoretically zero. What actually happens depends on the circuit
configuration and the device characteristics.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
I read in sci.electronics.design that Allan Herriman <allan.herriman.hat
es.spam@ctam.com.au.invalid> wrote (in <9g2qr0dl5q244i2c7vtn3l7jggjek4ou
6v@4ax.com>) about 'Differential Output', on Mon, 13 Dec 2004:

John, which ITU recommendation is that?
Click to expand...
The 126 dB limit for clicks was applied in UK at the time of de-
regulation, and I am not sure where it came from. The ITU document is
P360, and I don't have a copy of it. The predecessor had 135 dB for very
short clicks and 125 dB for longer disturbances.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
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