Multiple PAM8403 in parallel (same power supply)

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#2
No!!!

You are asking if a 5W power supply can supply enough power to supply 12 three watt amplifieirs?

It is not enough current to supply one board let alone 6 of them!!

You will need at least 8 amps to have enough power for that many boards.

jer 🙂
 
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#3
geraldfryjr said:
No!!!

You are asking if a 5W power supply can supply enough power to supply 12 three watt amplifieirs?

It is not enough current to supply one board let alone 6 of them!!

You will need at least 8 amps to have enough power for that many boards.

jer 🙂
Click to expand...

Hi geraldfryjr,
I think some info was misunderstood.
I'm using a multi voltage transformer with the position in 5volts

The transformer details are:
Model: P003C
PRI:100v-240v ~ 60/50Hz 0.25A
SEC:3/4.5/5/6/7.5/9/12V 1A (1000mA) 12VA

I already turned on 3 at the same time without any problem, but I wonder If i will have any problem if I turn on the 6 at the same time.

regards,
 
#4
You stated and I quote "I will like to know if it is possible to power up six PAM8403 amplifiers in parallel with one 5v 1000mA transformer."

5V at 1000ma "is" 5V at 1 amp and that is only 5 watts of power that you are trying to Feed Twelve 3watt amps with!!!

Your amps are going to need at least 36 to 40 watts of power to keep them happy

Even if you are only driving 8 ohm speakers the output of those amps are in the order of 1.4 watts each at 1%THD as this is the onset of clipping.

Here is the Data sheet for the PAM8403,

http://diodes.com/datasheets/PAM8403.pdf

And they are about 90% efficient at 8 ohms so you will need 10% more power than your total output into your load.

At 4 ohms they are only 80% efficient so you will need 20% more power than your total output.

For 4 ohms this comes to as per the data sheet, 2.5 watts X 12 or 30 watts and then you need another 20% at 6 watts so this comes to a total of 36 watts!
36 watts/ 5Volts=7.2 amps needed to power the amps.

If you are using 8 ohm speakers than it will be considerably a bit less at roughly half the current and power.

For 8 ohms this comes to as per the data sheet 1.4 watts X 12 or 16.8 watts and then you need another 10% at 1.68 watts so this comes to a total of 18.48 watts!
18.48 watts/ 5Volts=3.96 amps required to power the amps.

For the Record the power standard for a USB 3.0 port is only at .9 amps at 5Volts.
And .5 amps for a USB 2.0 port.

I am sure that you can turn them all on as there idle current is very low at 16ma., I am not sure if this is per chip or per amplifier section.
Lets say that it is for each amplifier section, and a total idle current of about 192ma. will be needed with no input signal.
This leaves no headroom for when you do start to drive the amplifiers.

FWIW

jer 🙂
 
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#6
Well, Since they are designed for 5V operation it is possible to power them off of a 5Volt line off of a Computer power supply.

That would be the Red wire that is 5V on the Molex connectors that go to your hard drives,CD's and Floppy's and graphic cards and such, and a Black wire would be ground.

This is a great option if you have an extra supply laying around doing nothing.

You also have to connect the Green wire from the motherboard connector on the supply's harness to a Black Ground wire as well in order to get the supply to turn on. if it is not connected to a motherboard or working computer setup.

Else you will have to get a bigger transformer and build a proper power supply for them.

They are only rated for a maximum input voltage of 6V.

And they are designed for no more than 5.5V for an operating voltage.

This is the common voltage range for TTL logic circuit's and is an all time standard for computers in general.

FWIW

jer 🙂
 
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