60Wx4 car radio Amplifier IC

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Hi, i´ve seen some Alpine car radios with 60W x4 , any one knows wich amplifier IC is used by these car radios?
Acording to my serchs I know that the TDA7560 is used on some Pionner car radios with 50Wx4 power out
But i didn´t find any information about this 60Wx4 IC

Any information is welcome

Tanks
:cool:
 
Some thoughts,

The difference between 60W and 50W is less than 1dB and is probably not noticeable. Anyway, these are just numbers. If you look at the beginning of the TDA7560 data sheet, it quotes outputs of between 30W and 80W depending on how it is measured.

If you consider, for arguments sake, that you have 14.4V and a balanced output and the ability to overcome Vbe drops, assuming then a 28.8Vp-p output swing, you'd have 52Wpeak into 4 ohms (26 real watts).

Assuming the only other thing you can do to extract more power (other than going class D), is to ensure optimum operating conditions, this would include supplying the highest rail voltage, having good heatsinking and running into heavier loads.

The TDA7560 claims to be able to do full rail swings, it can run into 2 ohm loads and will handle considerably more than a 14.4V rail. It doesn't appear there is much more to be gained going down this road until you move to higher supply rail(s).
 
If you consider, for arguments sake, that you have 14.4V and a balanced output and the ability to overcome Vbe drops, assuming then a 28.8Vp-p output swing, you'd have 52Wpeak into 4 ohms (26 real watts).

You mean a 14,4V voltage swing. Rest is correct.
And by "real watts" you mean RMS watts (on a sinusiodal wave).

space
 
Originally posted by space You mean a 14,4V voltage swing. Rest is correct.
But, if you have a balanced output, one half swings within the supply rail and the other half is equal but opposite in phase. Output is taken between them. VACp-p is 2 x supply (minus sundries).
And by "real watts" you mean RMS watts (on a sinusiodal wave).
Yes, I like to use WRMS but as far as I know, the term RMS applies to Volts, not Watts (a fine point in practice though :)).
 
I don't seem to get what you mean by balanced output. I thought you meant like a bridged output, which is what is found in most car radio IC's like the 7560. Both outputs swing within the supply rails from the midpoint and out but in opposite directions. Thereby the p-p max voltage is the same as supply voltage.
Are you supplying a second 14.4 volts, hence having a +/-14.4v supply? Please explain.

If you indeed get a 28.8 V p-p swing over 4 ohms then the Pmax/rms is double of what you wrote. (P=U^2/Z)

space
 
Maybe I get it now.
If we think of the two extremes, 1 and 2, where the outputs "+" and "-" shift from 0 to 14.4V and vice versa, then the combined change/shift/swing is 14.4V for each output but in opposite direction, so effectively the voltage change is 2*14.4V=28.8V. Is this what you mean?

Anyway the voltage difference between the two outputs, which is what gives you power, is never greater than 14.4V, and thereby P=U^2/Z upholds.

Guess it is all about how we define V p-p.One way is to say it is the change from one time to another which gives us V p-p = 28.8, or another way is to say it is the absolute max difference at a specific point in time which gives us 14.4v.

space
 
space said:
I don't seem to get what you mean by balanced output. I thought you meant like a bridged output, which is what is found in most car radio IC's like the 7560.


I haven't studied the chip topologies but have logically extrapolated the info. It's to be expected that manufacturers cite output power calculated from peak swings, especially for automotive where this is a bottleneck. It doesn't, I feel, stand to reason that a peak to peak swing could be used in a power calculation due to the zero crossing.

Where I come from, the standard 'high power' head unit (without inverter) claims 36W/4ohms which can be had from 12Vp or 24Vp-p. This could in fact be had from two equal and opposite separately amplified (internally) signals where the stages are grounded together and the signal is taken across their respective outputs.

Yes, I see now. This is a bridged arrangement. It is what I have been calling balanced. It has the swing of a diff amp but without the tail. I think we are on the same page.


Edit: just noticed your latest post.
 
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