0.5-1.5W mono chip amp

[trzn]

Hi,
I am looking for 12V mono chip amp. I am beginner, so I want something relatively simple. At the moment I am choosing between LM380, TDA7231, BA820M and OPA134. The last one is the most expensive and LM380 is the most popular among them.
Which one would provide the least background noise and which one would be the most energy efficient?

 

[nightanole]

http://www.sure-electronics.net/rf,audio/AA-AB008.pdf
6 bucks for 2 on ebay


2 watt at 5v, you could use a low noise 5v regulator to give it the 500ma it needs for peak output.


If you monkey around with the mini3 design you can get some really low distortion numbers


The Mini³ Portable Stereo Headphone Amplifier

http://www.analog.com/static/imported-files/data_sheets/AD8397.pdf

12vdc 310ma = 3.72 watt


As for your choices the LM380 is fixed gain of like 30, so if you fart on the input wire you will max it out. Id look at the LM4954


http://www.national.com/pf/LM/LM4954.html#Overview

It would need a regulator as well since it tops out at 9vdc in. But at least you can set the gain so your 2v rca signal is only upped to 5x instead of 30-50

 

[Minion]

The TDA2003 will give you about 6w with a 12v DC supply and they are about 50 cents a piece and only need a few external components ....


http://www.datasheetcatalog.org/datasheet/SGSThomsonMicroelectronics/mXutuqt.pdf

 

[pacificblue]

LM380, TDA7231, BA820M and OPA134.

Is that a list of available ICs where you live or do you also want advice on others?
Cancel the OPA134 from your list, because it is an opamp which will not give you the desired output. I assume the BA820 the same as TBA820.

If low noise is your main concern the other three are pretty similar as are most older ICs in that power range. You usually get 2..3 µV of input noise there. Lower noise is available from newer designs. That usually means SMD as in nightanole's proposals, so maybe not the best choice for a beginner. Newer designs in that power range are also usually class D and work form low supply voltages of 3..6 V, e. g. the LM48xx series.

 

[johnr66]

TDA7267A 16 pin DIP. Very low part count. Fully complementary output for max output voltage swing without extra parts. Fixed gain and no boucherot cell needed. Saves about 3 or four extra parts that an older design would require to match its performance. The old LM380 can never match its output power at a given supply voltage. I bought several chip amps from DigiKey to tinker with and the 7267A is my favorite of the 3 watt and under class.

One side of the chip has all pins as ground for easy heat sinking.

 

[trzn]

Ok, I found what I believe is the perfect chip for my needs - it is TDA7052A.
I will build amp according to the scheme in the datasheet. I have chosen these components from Mouser:
75-TVA1300-E3, Aluminum Electrolytic Capacitors - Leaded 50V 1.0 uF
75-MKT1813447064, Polyester Film Capacitors 0.47uF 63volts 5%
871-B37987F5104K, Multilayer Ceramic Capacitors (MLCC) - Leaded 0.1uF 50volts X7R 10%
647-PLF1C271MDO1, Aluminum Organic Polymer Capacitors 16volts 270uF Radial Leaded Poly
652-3386X-1-105LF, Trimmer Resistors - Single Turn 3/8 1Mohms 10% 0.5Watts Square
71-RN55E5001B, Metal Film Resistors 1/10watt 5Kohms .1% 25ppm
771-TDA7052AN, Audio Amplifiers 1W BTL MONO AMP W/VOL CTRL

Is it a good choice? Any recommendations?

I can choose all the components either from Mouser or from DigiKey (not some from one supplier and some from another).

 

[johnr66]

The TDA7052A will work, but only at 6 volts (you said you wanted a 12 volt supply) This 8 pin DIP BTL amp will overheat and shut down or fail if you try to operate with a 12 volt supply. It is too small and there is no provision for heat sinking, so you are pretty much limited to 6 volts.

 

[trzn]

Datasheet states that positive supply voltage range is between 4.5 and 18V. Does not that mean that it can operate on 12v?

Low Voltage 1W Mono Audio Amplifier Module (TDA7052) (3027) - 7052 (not 7052a, but very similar) and it says "Supply 3 – 15 V at < 300 mA".

The TDA7052A will work, but only at 6 volts (you said you wanted a 12 volt supply) This 8 pin DIP BTL amp will overheat and shut down or fail if you try to operate with a 12 volt supply. It is too small and there is no provision for heat sinking, so you are pretty much limited to 6 volts.

 

[pacificblue]

Does not that mean that it can operate on 12v?

Depends on the load impedance and the ambient temperature. There is a calculation example on page 5 in the datasheet with 8 Ohm and 6 V. Double the voltage means four times the heat dissipation which is about three times what the IC can dissipate at 25 °C.

 

[trzn]

I am lost...

 

[trzn]

Is that a list of available ICs where you live or do you also want advice on others?

I want advice on others. DigiKey, Mouser, Farnell - places where I can order stuff.

If low noise is your main concern

Yes, low noise and low quiescent current.

Lower noise is available from newer designs. That usually means SMD as in nightanole's proposals, so maybe not the best choice for a beginner.

I agree. Those chips are very old, more than 10 years old.
I could try SMD as long as it is not something like TQFN or similar to it.

Newer designs in that power range are also usually class D and work form low supply voltages of 3..6 V, e. g. the LM48xx series.

That's why I sadly cannot use class D amps, they operate on low voltages. And there is no point in using voltage regulators as they are not energy efficient.

 

[nightanole]

Cimarron Technology, Inc.

Could help you with some of the smt ones and convert them to usable.

 

[trzn]

So, which chip should I choose?

 

[nightanole]

Well your kinda flaky on your requirements. Its hard to do 1-2watt, 12v, very low noise. Why dont you relist your requirements alittle better then just "low".

1. quiescent/idle current requirement for the chip and power supply
2. sn ratio minimum
3. distortion maximum at 1.5 watt
4. package requirements. aka thru-hole, smt pads, sockets
5. minimum speaker impedance
6. B+ voltage source. I believe you said 12vdc

What gets me is the 12vdc source, yet wants low idle current. It sounds like a battery run time requirement, but a 12vdc battery that needs a really low idle current? You would think the rest of the system would be sucking 10x more then even a "high" idle current setup. Hell if you think about it, a solution with a 5-8vdc rail via a voltage regulator, would have a low idle current, since the chip is running at a lower voltage, and the regulator is doing almost nothing while the chip idles.

 

[trzn]

1. quiescent/idle current requirement for the chip and power supply -> the lower the better (<=30mA would be great)
2. sn ratio minimum -> reasonable (don't know much about it).
3. distortion maximum at 1.5 watt -> reasonable (don't know much about it).
4. package requirements. aka thru-hole, smt pads, sockets -> thru-hole would be the best option.
5. minimum speaker impedance -> 8ohms.
6. B+ voltage source. I believe you said 12vdc -> yes.

It sounds like a battery run time requirement, but a 12vdc battery that needs a really low idle current?

Correct.

You would think the rest of the system would be sucking 10x more then even a "high" idle current setup.

Each element powered from the battery consumes not more than 40mA.

Hell if you think about it, a solution with a 5-8vdc rail via a voltage regulator, would have a low idle current, since the chip is running at a lower voltage, and the regulator is doing almost nothing while the chip idles.

All I care is idle power consumption (so, if 5V amp + voltage regulator gives that, I am happy), no obvious hiss and reasonable distortion.

 

[nightanole]

Go with your TDA7052A or TDA7052. However use a 6vdc regulator to drop the 12v down to half. Idle current will not change from the stock 4ma with a regulator. It will just be 12vdc at 4ma instead of 6vdc at 4ma. I would also glue a hunk of aluminum to the top of it with jb weld or some other thermally conductive epoxy. I would want to push 1 watt through a unheatsinked dip8.


Hell now that i think about it you could just use a 6 volt zener to drop the voltage down to 6volts.

 

[johnr66]

I still say to go with the TDA7276A.
No voltage regulation needed
Easy to heat sink
Minimum parts
Low noise
Will deliver 1.5 watts into 8 ohms with 12 volt supply (no clipping at this output)
Watch this video:
YouTube - vegmatic1966's Channel

 

[trzn]

At the moment I am trying to do it with 7052A.
That's what I got for now: http://img535.imageshack.us/img535/8213/7052av2.png.

 

[nightanole]

The problem with the tda7267a (tda7276 is a motor speed control) is it idles at 35ma, vs 5ma of his 7052a. Hes going for an extended run time option. I think all it does is beep every once in awhile or something.

 

[pacificblue]

That's what I got for now:

If you have more capacitance on the 7806's output than on the input, you should add a flyback diode.

Shouldn't there be an input resistor to ground?

The symbol you used for the input is the ground symbol