TA8275 mute pin

[slmnklyc]

Ok.I see now.
Thanks tomchr..
But I don't want to put a mute switch for The amp.
I just want to use the mute function on start up with a very short time and Automatically it will mute and then amplifier will begin to play.Like the option on lm3886 chip..
I think simple setup is not possible for my purpose.
So I think I will give up I will just using mute pin floating..

 

[slmnklyc]

Did you see my post in the other thread where you asked about the mute function? Here's a link to the post: Can mute pin on LM3886 (etc.) eliminate popping?

Tom

Maybe it is simple question but
If I connect the mute pin to R+C+'pre-gnd , does this give me a little 'mute on time' until the cap will charge,and after charged the cap the internal current will continue to flow to internal transistor and amp begins to play??

 

[tomchr]

In that case, you don't need an RC. All you need is the 'C'. C4 in the data sheet to be specific.

The internal 100 uA current source will charge C4. Once the voltage on C4 reaches 3.2 V (high temp), the amp will un-mute.

Recall that C = Q/V and Q = i*t, thus, C = (i*t)/V

So if you want a 2-second un-mute time you'll want:
C4 = (100e-6 * 2)/3.2 = 62.5 uF.

I'd probably set C4 = 100 uF and call it good. Or 47 uF if you don't want to wait as long. The longest you'd ever have to wait with C4 = 100 uF is determined by the Vmute = 4.6 V (low temp) case. That'd give you: t = VC/i <-> t = 4.6*100e-6/100e-6 = 4.6 seconds.

Tom

 

[slmnklyc]

Really thanks tomchr you were very helpfull..

 

[tomchr]

You're quite welcome.