TPA3118D2

[xrk971]

You are right, that is worst case, for music, probably no heat sink needed. It has auto thermal shutdown too so no harm in pushing it. Some deep bass notes may cause it to trip if built in thermistor senses 150 C or above. I am kind of getting excited about making my own pcb now that folks on this forum have given me tips on Eagle and where to get them fabbed. I always thought doing my own smd pcb was out of my league but it is looking more and more like a possibility. I want to make this thing as small as possible for grins like maybe 1.5 x 2 in ? The inductors and power caps are the size limiters. If I go with flying leads I can save a lot of real estate and costs by not having screw terminals. The TPA3116D2 is a 50 watt per channel chip that is the same pinout and size. A 50 watt hifi amp the size of a large postage stamp is nuts.

[xrk971]

Life has been getting in the way of diy'ing lately and it has been very hard to find time to do precision work. Having to sit down with magnifying goggles, have undisturbed quiet time, and clear eyes and mind to manipulate a 0.6mm pitch lead with a fat soldering tip is tough. Nonetheless, I have made some progress and have about 6 leads to go on the 32 lead flip chip dead bug amp mounted on foam core board.

The 'large' bare copper wires are the main leads running from the amp to the inductors - these are 22 awg. Using that for Vcc and ground bus.

[radiosmuck]

Hi,
what is the difference between a TPA3123d2 board available on ebay for
$16, shipping included, and the TPA3118d2 you guys are challenging yourselves with?
2x50 w Stereo Class D Audio Power Amplifier Circuit Board TI TPA3123 | eBay

[DUG]

http://www.ti.com/lit/ds/symlink/tpa3123d2.pdf
http://www.ti.com/lit/ds/symlink/tpa3116d2.pdf

1. The modulation scheme is different for the ...16d2 part...read data sheet carefully

2. ...23d2 board at 50W out (@10% thd by the way) would dissipate close to 5W
I don't see much of a heat sink other than the board...hope they did it right.

3. We don't know what parts are used in that design...are the filter inductors able to handle 6A without saturation...are the power supply filter caps low esr types...what is the low end roll-off on the input caps...so many questions.

4. Where is the fun in just buying something you can make?

That is why it is called diy and not ibioeb (I Bought It On E-Bay)

[radiosmuck]

I could make a reasonable enclosure for my ebay purchase, but I could not assemble a board, I made a horrible mess of replacing some components in a tube amp!
Would making a box qualify as diy as does pimping up a Lepai 2020a? ;-)
For the price of Chinese d-amp boards is it worth studying the specs? It is very hard to be disappointed.

[DUG]

If your diy project is to put that amp in a box then that is what it is.

No-one should have a problem with that.

I can't build an integrated circuit. We all have to start with whatever building blocks we can deal with...or wish to attempt.

Sometime we fail. Sometimes we don't.

"It is better to have tried and failed than never to have failed at all."



That is DIY.

Be proud of (and share) what you can do.

Have fun

[xrk971]

I finally had time to put the last "wire bonds" onto the upside down SMD flip chip. I put my 10x loupe on and carefully looked the connections over, and compared to schematic, then used a continuity tester and checked to see if "ground" shows up on any of the pins that it shouldn't. Ugg, one of the pins that should show +100k ohm on the gain setting section went to GND.

It turns out one of the 1 uF caps was bad and shorted (I probably fried it by applying too much heat during soldering). I swapped out the bad cap. Connected my foam core micro 14-inch Cornu spiral horn speakers, connected my old linear (transformer and 7812 based) bench power supply, connected to balanced inputs to an old headphone 3.5 mm jack and cable, plugged that into my source (a BB). Put on Led Zeppelin's "Stairway to Heaven" for the inaugural song. Crossed my fingers, pushed the power button on the supply. The LED lit, and good clean sounding Robert Plant's voice filled the room! I smiled and had a big ear-to-ear grin.

My first Class D amp, and I did it with a dead bug point-to-point wiring with all SMD components! The whole business with gluing the SMD parts to a piece of paper with the schematic drawn on it, and soldering point-to-point connections works! It sounds great. I did not take it too loud as I do not have any heat sinking or even solder connecting the powerpad to the groundplane for dissipation. It got pretty loud still.

If I had dedicated time, this would not have taken too long. But having to work in 1 hr increments took 8 hrs to do this. Being smarter and learning the tricks, I think I can go faster next time. Next time I will buy a 0.015 inch tip for my soldering iron and 0.015 in dia solder. Anyhow, here is the picture of the completed Foam Core Amp, and the Foam Core Audio System.
Did you guys have doubts that this would work?

[DUG]

Congrats

Always nice to get sound and not smoke.

[DUG]

and next is?

[xrk971]

Thanks Dug. It always amazes me when a circuit works the first time. Next is the TPA3116D2 mounted on a nicely designed PCB provided by my benefactor