I wanted to procure a few low-power class-D audio amplifiers for a project I was working on. I needed a two-channel amplifier, a few Watts per channel, 4- or 8-Ω load (TBD later), and supply voltage 5V to 10V. I knew there were probably more devices available that were capable of operating at 5V than at 10V since the IC process that works at low voltage is less expensive, so it's used more often.
For this exploration of devices, let's pick on NXP, which is where all these screen shots came from. It could just as well be one of the other guys. I happened to pick NXP first — so just my two cents worth of frustration taken out on it. Let's start on its home page:
OK, this looks promising. There's a line item on the left that says amplifiers. Great — I'll probably be able to look at a chart that will give a quick overview. Then I'll be able to drill down and have my device selected with just a few clicks. I'll be able to see what is available and probably get an idea of packages and a ballpark price.
So I'll just click on amplifiers; and I go to this:
That looks good. Now I just pick the audio products as opposed to CATV or op-amp devices.
That takes me to a more detailed selection. Still looks promising. No reason to worry because there's what I want — class-D — and it looks as if there are 16 versions of such devices. I'll click on that choice.
And I get to read a nice overview of the devices. Hmm… not much especially useful technical info here except that they make devices from 0.4W up to a couple hundred Watts. Well, good; should be parts in my power range. Must be the next tab on that chart that I want, where it says “Products.” Yes, please, I would like some products. I believe that's way I came to this site, as I recall.
So I'll just click on the tab and…
Uh-oh. So apparently NXP has some very muscular class-D amps (75W, 150W, 210W, etc.) and a few other devices that they just mention in passing. I say that because there is no information except “class-D amplifier” — which I sort of would have guessed, what with this being the portion of the NXP site that promotes class-D amplifiers. So I guess I am obliged to click on any line items of interest (they are hyperlinks) to learn more. That could be a tedious, dead-end process, so, so, so…
But wait! There is another tab that I overlooked: “Parametric search.” That should let me zero in on just what I wanted (regarding supply voltage and output power) at the beginning of this odyssey. I'll just click the tab and…
Oh, crap… what the… Another chart containing no useful info at all.
So, let's summarize what we've learned:
Now, that's not enirely fair, because I've seen this elsewhere. I really don't want to pick on NXP. There are other sites that have apparently been created by people who lack a clear understanding of how engineers want to get information. Please post your comments and let me know your experiences in this regard. Perhaps, if some of the folks at the head-offices of some of our favorite semiconductor companies see this, they will make some changes.