SMPS - switching frequency, ripple, leakage tradeoffs for class-D?

[nrabbit]

I recently finished the tpa3255 reference design here

Are there any good reads on what to prioritize when looking at SMPS?

Can it be drilled down in to comparing a few stats? Or is it harder to quantify than that?

Or is it mostly down to the design of an amp being more or less sensitive to power quality?


If you look at a big name manufacturer like Benchmark they seem to favor higher switching frequencies and thus smaller transformers here

I'd like to go with a smaller, higher frequency smps (I don't care too much about wattage) like this: CFM150S480-B

It's only 4 inches x 2 inches and has a switching frequency of 115khz and very low idle power draw, but it has a ripple of 1%.

 

[bucks bunny]

I do not think that the specified ripple tells you much about audible noise created by the smps. But the tiny standby power consumption is an indicator for "burst-mode" operation and may or may not generate annoying noise in case of no load.
Besides this vague issue it looks like good value for the money.

 

[nrabbit]

Thanks. I had not heard of burst mode. I will be on the lookout for this in the future. Thankfully my amp draws about 8 watts at idle so I don't think it will kick in.


I think I found enough of an answer to my question. I was looking for power supply rejection ratio


Switching frequency seems to be a function of transformer size and smaller transformers emit less noise.