Help on TDA7560

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Hi, I'm new to DIY audio ...
I have a TDA7560 based amp as my 1st project,
I got some problem with it & would be very much grateful if anyone can help me.

TDA7560 datasheet shows
http://pdf1.alldatasheet.com/datasheet-pdf/view/25157/STMICROELECTRONICS/TDA7384.html

ABSOLUTE MAXIMUM RATINGS
Vcc ------------Operating Supply Voltage------------18 V
Vcc(dc)---------DC Supply Voltage-------------------28 V
So, what's the maximum dc voltage(from a rectifier) I can apply to the ckt??
If it is 28v what's the significance of the max 18v?
(can I get a relation between the two?)

(It is given)
FEATURES:
4*50W/4 ohm Max
4*30W/4 ohm @ 14.4V,1khz,10%
Is the above mentioned 14.4V Vcc or Vcc(dc)??

I need to power a pair of fullrange speaker of 40W nominal each,
so, what should be the ideal power of the amp & the i/p dc volt to the ckt??
:)
 
You should design the power supply for a maximum of 18 V nominal. 28 V is the no-load voltage your power supply should not surpass, i. e. (nominal transformer voltage + mains fluctuation + transformer regulation) * 1,41.

The 14,4 V would be Vcc.

There is no ideal voltage, as long as you remain within the specified range. A 12 V transformer with 15 A or more should be just right to remain below the 28 V limit unloaded and bring you into the specified 13,2 to 14,4 V range when loaded.
 
This chip is designed for single supply (eg, automotive audio). There are much better chips for a pair of speakers if you plan on using them in a non-mobile environment.

Also, the datasheet you linked to is incorrect. The correct link would be:
http://www.datasheetcatalog.com/datasheets_pdf/T/D/A/7/TDA7560.shtml

According to the datasheet, it can handle 8V p-p input, although there is no more info on whether that is the level required to get maximum output.
 
You can definitely use 14 or 15V. As pacificblue said, a 12V transformer would be possible, as loaded output would be about 16V. Unloaded, it would probably be about 18V, so that's probably as high as you would want to go.

Looking at the output power vs supply voltage graph, at 16V supply, max output into 4ohm speakers is 60W. You might assume (since they don't tell you) that that output is for 8V input. So to get 40W, you would need an input of about 5.3V.
 
hello.
the data sheet says you can get round about 23watt(at 1%distortion) with 4ohm speakers and 14,4v(dc) supplyvoltage with this poweramp.
the voltage gain is internally fixed to 26db (=20 times,e.g. 1v input gives you 20v output).
the input caps (100nf) are a little bit small,for more bass you can use 220nf or 470nf as you like.................
greetings.........
 
Thanks Redshift..

the tda7560 is designed to have supply from a car battery(about 12v dc).........
..........so if I use a 12v transformer, on rectification the o/p should be (12*2/pi=) 7.64v dc ...........or am I wrong??









.........did u say about other chips better than tda7560 for non-mobile use??:confused:
 
most reputable manufacturers will state the THD to match the power specification.
Many will give maximum power @ 0.x% THD and with nominal mains input voltage.
x can be any value 1 or 2 or 5 or 01(=0.01%)
It is also normal to expect the test frequency (sinewave) to be stated as well and maybe a range of alternative frequencies.
 
4 channels * 23 W = 92 W
12 V * 4 A = 48 VA

It will work. It would work better, with a transformer rating bigger than or equal to the combined output power.

zinblade19 said:
(transformer with higher current rating isn't available here)
Originally posted by kuldeepsingh in http://www.diyaudio.com/forums/showthread.php?postid=1786795#post1786795
Hi guys, problem here is everything is available but u have to go in deep streets in electronics market, say i in Chennai went to Richie street where hundreds of small shops are there, but u'll get everything from toriods to Panasonic caps.
I had the same impression, when I was in India. You can get anything and also at any time of the day, if you know, where to look for it. Or if somebody, who knows, where to look for it, helps you to find it, which was the case for me.
 
car radio amp chips are quite nice as they have the ability of pushing.. HUGE repetitive currents.
otherwise, by quality it is not the best option.
however, it has well enough grunt to power some decent subs or speakers.

I'd say substract 4 volts from the supply voltage. say be it 16 volts, then it comes down to 12 volt at output peak to peak. the 4 ohm load -witch is, when considering a speaker is rarely 4 ohms- will yield 3 amp current. Gives 36 watts, but that would be at about 10% thd.

thing is, I'm sure it will not do more than 25 into a resistive 4 ohm load within reasonable THD.

but, that should not give any problems. Mostly few watts is all that is needed.
some of these chips are stable at 2 ohm even in BTL. spooky if you ask me.

The datasheets specify an absolute maximum supply voltage that the chip can survive while no signal is applied, and no load.
That is 28 volts.
never even consider that, it is just to show the voltage spike it can handle when the powersupply comes alive. like an smps. that has a huge spike when turned on.
the absolute maximum 18 volt supply voltage when it is not muted, has signal applied, and has a load on output is what You should never ever exceed.
A 11.5 volt halogen lamp transformator would be the ideal choice.
Probably in the 100 VA range to be sure.
 
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