My first Class D from scratch...

[luka]

Originally posted by Tekko
Terrible layout can also cause ringing like this.

Also you need to increase the switching freq to atleast 400KHz to be able to play fullrange satisfactory, at just 170KHz, the power bandwidth makes the amp drop off in audio level as you hit just a few KHz.

Another improvement would be making it self oscillating, like UcD, SODA or SODFA, clocked designs are usually only used in car bass boosters since EMI tend to be much higvher than self oscillating.

What 400k?? 250k is enough for full range, try and you will see. But smaller inductor can be used at 400k

[Tekko]

For you yes, but not for me, for me a class d amp below 700KHz is only good for subwoofer, and above to be fullrange, actually it have to be above 1MHz before i start calling it a hifi class d amp.

[Tim__x]

The higher the switching frequency the greater the distortion attributable to a given deadtime. With today's semiconductors 400k is a pretty good balance, even 200k can be made to prett high performance.
1Mhz switching is very likely to give inferior performance.