Microspeaker Control Chip

[DonH56]

Interesting article (and sales pitch, natch) about optimizing (micro-)speaker performance in things like cell phones. I have read about other class D amps using switching or tracking rails but think this is the first time I've seen it in a commercial product. Have not really been keeping up, however, too many work hours. Do any of the larger (i.e. not for microspeaker) commercial class D audio amplifiers available now use G or H to extend efficiency even further? Seems like a good plan for improving low-power efficiency (where class D is at its lowest, though still usually better than AB).

https://www.electronicdesign.com/in...3391ea77f250427fca&oly_enc_id=2127J7762501H5G

FYI - Don

 

[KSTR]

Merus Audio MA12040 chip has been around for quite some time, using multilevel switching to decrease losses and EMI. Infinion has bought up this startup company from Denmark in 2018.
With up to 18V supply, the chip is quite capable (40W) and will find (or already has found) its use in larger powered speakers (Bluetooth etc).
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d462696dbf120169b4f8f7524db9

 

[DonH56]

Yes, good catch, and I should have mentioned that. What they call multilevel has been around a long time but yes it is a neat idea. Aligning the different levels is tricky, natch, and the times I tried it I am not sure I got it where I wanted it. But it does save power especially in a BTL output approach. However, I do not think that is the same thing as actually switching (or moving) the supply rail for the output, which is what Maxim is claiming in their class DG approach. I may have to dig up some papers but they're at home or online and I don't want to use my work IEEE subscription for personal stuff (they track it, natch).

 

[restorer-john]

Interesting Don, thanks for posting. I would say the main business $ will be in characterising chinese zero-spec drivers for use in portable and small devices.

Have a look at the "fake lab" in the second video. It's funny, a few instruments randomly placed on the bench, some power tools, a soccer ball, leaky tins of paint and a flat panel with Maxim's logo on it.

https://www.maximintegrated.com/en/...nt/dsm-laser-characterization.html#popupmodal