Anyone ever dabbled with Class D amplifiers?

[Gurner]

So I ordered some samples from Maxim - included in the shopping list a Class D 1.8W amplifier.

It arrived - just 3mm long - eek!

First problem - "Hmm me needs a breadboard adapter " - couldn't find a MSOP10/DIL10 (0.5mm pitch - or 0.019685" for those still working in base 32 type formats  - double eek!), so in the end I rolled my own in Eagle & etched it tonight - not an enjoyable experience at all...

[/URL]

....it just looks plain wrong - ie this thing handling 1.8W!!

(Oh btw, I've since reflowed those dryish looking 0.1" header pin solder joints!)

Just curious if anyone has travelled down this path & what their experience was?

[Taylor]

Haven't yet, but if the chipamp projects I'm working on turn out to be popular, I'd like to do a bigger version using class D, like 100w in a 125b.  

Here's a Class D chip I was looking at. 1" square, 50 watts, runs on a single-sided supply:

http://datasheets.maxim-ic.com/en/ds/MAX9709.pdf

[Gurner]

Haven't yet, but if the chipamp projects I'm working on turn out to be popular, I'd like to do a bigger version using class D, like 100w in a 125b.  

Here's a Class D chip I was looking at. 1" square, 50 watts, runs on a single-sided supply:

http://datasheets.maxim-ic.com/en/ds/MAX9709.pdf

Cool.

This is actually my second attempt - the one the other night lasted all of 5 minutes before I nuked it (hey ho - just as well it was gratis ..... that's what learnings all about!)- in its oh so short life, I managed to scope its output - it looks well weird to these aged analogue eyes, seeing something akin to a digital signal on the audio amps output legs!

[Gurner]

well, put it on breadboard - fired it up, attached a speaker - works (& why shouldn't it! )
Here's what's being fed out of the amp to the two speaker wires!



Yeah, yeah ...I know the speaker acts as a low pass filter & essentially averages it out, but nevertheless - Mental.

[jasperoosthoek]

Yep, built a couple for my lead acid gel battery powered boombox.

I've first were SMDs, about 10 watts or so into 8 ohm speakers running on 12 volts smaller than the nail on my pinkie!

I overheated one with my soldering iron and blew up the second batch when I connected the battery in reserve.

Then I found the TA2020 chip from tripath. A 2x20 watts chip in a DIP package . I ordered a kit from www.47hz.com (cannot check the link right now). It's been running fine for 2 years now.

They're not magic just like laptop switching power supplies based on similar principles are not magic.  

[petemoore]

http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=203&CFID=21177461&CFTOKEN=23959535
 
  Dabbled as far as reading up and reviewing the reviews.
 

[jasperoosthoek]

The correct link is www.41hz.com

[Cliff Schecht]

Class D stuff is pretty cool, but the really cool stuff is class G/H style amplifiers where they modulate the supply voltage to keep the device at the highest efficiency at all times. The supply voltage literally follows the output voltage to keep the amplifier operating in the linear region but with as little necessary wasted headroom as possible. More effiecient than class AB, less efficient than D, but a lot less noisy than D as well (better THD specs too IIRC).