New classD amp: Gemincore of CL3

[vroum90]

hello,

A new classD manufacturer: CL3 , a french society

They use a full bridge technology. Gemincore sound very well.

Take a look at www.Cl3.FR

@++ Seb

[classd4sure]

It seems inherently limited with that topology.
They ought to have answered the question of that not becomming more popular themselves.

Seems as though they've gone and patented the source follower? What's next.

[koolkid731]

They can't patent the source follower circuit as it's been around. The conclusion part of the paper does ask the question why people don't use it more often.

[koolkid731]

I just looked at Ambruschi US application dated Feb 2004.

Complementary totem pole has been used in class AB amps, including MOSFET output stage, and in many bipolar driver stages driving mosfet.

The question is what is new in CL3 circuit? The fact Ambruschi learned about its minimum shoot-thru doesn't make it new, only new to him.

Complementay totem poles have been around in the 70's at least, in bipolar output stage. Now isn't that obvious that mosfets can also be used instead of bipolar?

[classd4sure]

Maybe it's the driver that would be "novel"? Seems that would be the trickier part with that kind of output stage?

[koolkid731]

CL3 did get a US patent. Whether it's enforceable is another issue.

No big deal. Pfet is more expensive. And there're better ways to switch a totem pole without shoot-thru current.

[classd4sure]

Yeh, I still find it inherently limited, nothing special. The design is likely maxed out already.

[sx881663]

If you think of this as just an impedance conversion then it looks to have some very real advantages. The drive can be simplified and optimized very nicely. The problems are exceeding the gate voltage when the output can’t track (shorted output) and the necessity of driving over the rail voltage to get full on at the rails. Also the fact that hi voltage “P” type device selection is very limited. These are the real stumbling blocks to this design. A transformer drive with a step up ratio would be an easy solution to some of the problems. This could also generate the oposite phase for bridge drive.
This could be the configuration of choice for lower power. Maybe up to 24 volts total? With proper design in a full bridge this could give well over 200 watts into 4 ohms. This would be enough for serious consideration I would think.
I will have to think about this a lot more.
Roger

[classd4sure]

heh heh.... can tell you're going after this! Right on. Xformer coupling is likely the simplest way and a good one I think.

Now what do you suppose they allude to when it comes to that 1000W burst power? PMPO?

[sx881663]

Lets see, Distortion @ 10% (far into clipping) load at 2 ohms, 2ms burst and +3db to cover advertising claims and you have it. Don't even have to resort to peak power.
Roger