For the do it yourselfer I thought some of you might be interested in this. http://cache.national.com/ds/LM/LM4651.pdf

To get full use out of it you would need to design a power supply but it will also work with +/- 12V just reduced power output. Under voltage lockout is 10.5V


Build a nice power supply and replace the LM4652 with some different transistors and you could have a powerful amplifier.


Modified by nsxxtreme at 12:59 PM 7/1/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by neo_ &raquo;</TD></TR><TR><TD CLASS="quote">Joking, right?</TD></TR></TABLE>
No, there is a completely laid out example at the end even the board layout. The circuit consists mainly of just the two IC's. Your looking at $30 worth of parts not counting the boards. Some people like to do things on there own. You could also learn how a class D amplifier works from that documentation. You know how one works you pretty much know how they all work.

 

There is usually three main sections to an amplifier.

1. pre-amplifier this is where any signal processing gets done. Bass boost, Treble boost, ect.

2. Amplifier - This is where the main amplification gets done.

3. Power supply - This is essentially an amplifier also, it raises the 12VDC up to +30V and -30V the amount depends on the amount of amplification needed.

It doesn't matter if its an A, B, AB, or D they will all have these sections. The paper I linked to is #2 just the amplifier. The Power supply would go to the +Vcc -Vee on the IC.

That paper shows how Class D amplifiers work and why they are as efficient as they are. Instead of being a linear amplifier. They chop the signal up at a high frequency. This is filtered out at the ouput. You will notice a low pass passive filter on the ouput of the amplifier. This removes the high frequency components.


A good view of the sections can be seen here https://honda-tech.com/zerothread?id=1267955

From left to right Pre-amplifier, Amplifier, Power supply

 

Althought I like to tinker, this would be beyond my abilities. I do give you props for even posting it! There's no limit to what you can build given a problem!!

 

Hmm, will have to come back to this when I have more time and take a closer look