David Grant wrote:
I'm designing/constructing a 100W Class-D Power amp for my final year ECE
design project. I've done some looking through NGs, google and the campus
library for research material, but haven't found any very recent
information. Have there been any major advances in the past two years for
Class-D amps? If so are they documented anywhere?

Yes, there have been lots and lots of AES presentations and papers.

Johan Gaboriau, Xiofan Fei and Eric Wallburger from Cirrus Logic.
High Performance PWM Power Audio Amplifier. AES preprint 5428 (2001).

All of the Zetex data sheets.

Frank Christensen, et al, PSCPWM-Based Switching Audio Power Amplifiers.
Preprint #5040 (1999).

Michael Score, Donald Dapkus, and Timothy Darling from TI, Class D Amplifiers:
System Considerations. Preprint #5041 (1999)

Karsten Nielsen and Lars Fenger from B&O.
The Active pulse modulated Transducer, A novel audio power conversion system
architecture. Preprint 5866 (2004).

Steven Harris, Jack Anderson, and Daniel Cheng of D2Audio. Intelligent Class
D Amplifier Controller Integrated Circuit as an Ingredient Technology for
Multi-Channel Amplifier Modules of Greater than 50Watts/Channel. Preprint 5947.

This is by no means complete... this is just a five-minute search through
the AES preprints from the past few shows that I decided to keep. There
are probably a dozen or so more Class D papers that I decided not to keep.
This is a really, really hot field right now because everybody is wanting
higher and higher efficiency amplifiers for battery-powered devices.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 28 Sep 2004 13:50:55 -0400, (Scott Dorsey) wrote:

David Grant wrote:
I'm designing/constructing a 100W Class-D Power amp for my final year ECE
design project. I've done some looking through NGs, google and the campus
library for research material, but haven't found any very recent
information. Have there been any major advances in the past two years for
Class-D amps? If so are they documented anywhere?

I don't know about "in the past two years" but TI
(http://www.ti.com) came out with a lot of Class D stuff in the last
five to eight years or so.

This is a really, really hot field right now because everybody is wanting
higher and higher efficiency amplifiers for battery-powered devices.

Not just for that, but for six powerful, efficient amps to put in a
small box that won't get too hot for home theater/5.1 systems.

--scott

-----
http://mindspring.com/~benbradley

On 28 Sep 2004 13:50:55 -0400, (Scott Dorsey) wrote:

David Grant wrote:
I'm designing/constructing a 100W Class-D Power amp for my final year ECE
design project. I've done some looking through NGs, google and the campus
library for research material, but haven't found any very recent
information. Have there been any major advances in the past two years for
Class-D amps? If so are they documented anywhere?

I don't know about "in the past two years" but TI
(http://www.ti.com) came out with a lot of Class D stuff in the last
five to eight years or so.

This is a really, really hot field right now because everybody is wanting
higher and higher efficiency amplifiers for battery-powered devices.

Not just for that, but for six powerful, efficient amps to put in a
small box that won't get too hot for home theater/5.1 systems.

--scott

-----
http://mindspring.com/~benbradley

Ben Bradley wrote:
On 28 Sep 2004 13:50:55 -0400, (Scott Dorsey) wrote:

David Grant wrote:
I'm designing/constructing a 100W Class-D Power amp for my final year ECE
design project. I've done some looking through NGs, google and the campus
library for research material, but haven't found any very recent
information. Have there been any major advances in the past two years for
Class-D amps? If so are they documented anywhere?

I don't know about "in the past two years" but TI
(http://www.ti.com) came out with a lot of Class D stuff in the last
five to eight years or so.

Oh yeah, and there are some papers on the slate for San Francisco this month
that look interesting:


11:30 am
K-6 Improved Analog Class-D Amplifier with Carrier Symmetry
Modulation€”Bruce Candy, Halcro, Torrensville, Australia; S. M. Cox,
University of Adelaide, Adelaide, Australia
A novel analog class-D amplifier has been developed that produces
low distortion. The structure follows the well known, prior art class-D
structures with negative feedback but includes modulation of the
symmetry of the carrier oscillator waveform by a derivative of the
input signal. This compensates a nonlinear phase modulation effect
that is intrinsic to the prior art structures. The improvement is
substantial at very low extra cost.
Convention Paper 6260

Z7-2 Class D Amplifier with Zero Switching Ripple€”Eric
Mendenhall, Audio Power Electronics, Dove Canyon, CA, USA
Class D amplifiers are used for their high efficiency, but they have
some undesirable characteristics, one of these being the residual
switching frequency ripple. This paper shows a method of switching
frequency ripple reduction by means of ripple steering. With this
technique a second output is constructed, into which the switching
ripple is steered, substantially relieving the main output from a major
artifact of Class D operation.
Convention Paper 6300
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Ben Bradley wrote:
On 28 Sep 2004 13:50:55 -0400, (Scott Dorsey) wrote:

David Grant wrote:
I'm designing/constructing a 100W Class-D Power amp for my final year ECE
design project. I've done some looking through NGs, google and the campus
library for research material, but haven't found any very recent
information. Have there been any major advances in the past two years for
Class-D amps? If so are they documented anywhere?

I don't know about "in the past two years" but TI
(http://www.ti.com) came out with a lot of Class D stuff in the last
five to eight years or so.

Oh yeah, and there are some papers on the slate for San Francisco this month
that look interesting:


11:30 am
K-6 Improved Analog Class-D Amplifier with Carrier Symmetry
Modulation€”Bruce Candy, Halcro, Torrensville, Australia; S. M. Cox,
University of Adelaide, Adelaide, Australia
A novel analog class-D amplifier has been developed that produces
low distortion. The structure follows the well known, prior art class-D
structures with negative feedback but includes modulation of the
symmetry of the carrier oscillator waveform by a derivative of the
input signal. This compensates a nonlinear phase modulation effect
that is intrinsic to the prior art structures. The improvement is
substantial at very low extra cost.
Convention Paper 6260

Z7-2 Class D Amplifier with Zero Switching Ripple€”Eric
Mendenhall, Audio Power Electronics, Dove Canyon, CA, USA
Class D amplifiers are used for their high efficiency, but they have
some undesirable characteristics, one of these being the residual
switching frequency ripple. This paper shows a method of switching
frequency ripple reduction by means of ripple steering. With this
technique a second output is constructed, into which the switching
ripple is steered, substantially relieving the main output from a major
artifact of Class D operation.
Convention Paper 6300
--
"C'est un Nagra. C'est suisse, et tres, tres precis."