Class D - needs SMD?

[bassetrox]

HI, I'm looking at Class D designs out of interest (poss with a long term objective of building a power amp, for fun.

I get the principle, I dont know anything about the practicalities.

I was once told that its impossible to build a decent class without using SMD because of the high switching speeds involved. (i think it was the chappie at Elliott Sound Products - The Audio Pages (Main Index)) Is this true? Why? I also saw someone trying to breadboard a philips UCD once, though I dont know if it worked!

 

[Pafi]

SMD is not neccessary, but it makes things much easier. Smaller parasitic inductance, space for continuous ground plane, easier assembling and easier observation during measurement. With very much experience (or huge luck) it's possible to build some good ClassD with TH components. And some circuits are less sensitive than others.

 

[nigelwright7557]

I managed a thru hole irs2092 project OK.
So long as you dont have really long tracks it isnt a problem.

I prefer thru hole as I can socket the irs2092 for ease of replacement if I blow one up.
Which is easily done if you dont discharge capacitors before removing one and inserting another.

 

[Sch3mat1c]

In fact, I've succeeded in breadboarding moderately powered class D circuitry. But that takes more layout talent than any through-hole design does.

SMT is nice because it's small, doesn't require a mess of holes* and trimmed leads, and it's still quite easy to solder (if you pick your components wisely, that is).

*Holes being a problem for homemade PCBs (all that damn drilling!). This is replaced by many tedious vias, but you still use fewer holes so it's easier to build.

Tim