Thoughts on best Class D power supply?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi Pafi,

Can you explain your comment? I hope that Texas Instruments would design a power supply with low noise generation and stable output to support their Class D amplifier designs.

Thanks,

Hi,

I'm sure it is usable for their amplifiers, but this doesn't mean, doesn't require being especially low noise. The test results only contain differential noise measurements, limited to 20 MHz bandwith, and those are not quite impressive. No data about common mode noise current at all, which causes the most EMI problem. Efficiency is also not too high, 85 % overall.

The most obvious problem with it is the fly-back aux power. The very high primary to secondary stray capacitance with high dv/dt switching node makes a high common mode noise, that is later attenuated by L2,L5, at the expense of making all primary circuitry (including PGND node) "hot", but in a modern, controlled slew rate LLC design it is much lower by default, not requiring nasty and later becoming problematic trick.
...
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.