>-----Original Message-----
>From: Martin Klingensmith [mailto:martin@NNYTECH.NET]
>Sent: 13 July 2004 14:20
>To: PICLIST@MITVMA.MIT.EDU
>Subject: Re: [EE:] Design Challenge - best PWM
>
>
>All this talk of PWM reminds me that I have an H bridge class
>D amplifier I have been trying to build. Well, I had it
>working but I shorted out the one of the MOSFETs, giving a
>nice chain reaction blowing just about all the chips. The
>sound quality was not very good, due obviously to my 70KHz
>carrier. So since there are some people here who seem to know
>a lot of PWM generator designs, can I ask what you would use
>for a ramp oscillator and comparator running at 150-200KHz?
>I'd like to see what comes up here. Price isn't an issue
>really, it's a one-off amplifier. I should be all set with the
>power stage unless someone has a really nice idea for that.
>Thanks in advance.

Sorry, not a direct answer to your question, but there are a surprising
number of integrated class D solutions around now:

Maxim have several low power devices, up to 15Watts RMS/channel
http://www.maxim-ic.com/AudioVideo.cfm

National have a 170Watt driver device and a matched power stage that may be
of some use?
http://cache.national.com/ds/LM/LM4651.pdf

Philips also have some higher power Class D amplifiers
http://www.semiconductors.philips.com/catalog/282/41685/34068/31627/index.ht
ml#31627


A couple of links to Class D designs:

An "open source" Class D hifi design
http://listen.to/audioexperiment

Schematics of a comercial Class D amp
http://www.crestaudio.com/media/pdf/lt_schematic.pdf

Regards

Mike

=======================================================================
This e-mail is intended for the person it is addressed to only. The
information contained in it may be confidential and/or protected by
law. If you are not the intended recipient of this message, you must
not make any use of this information, or copy or show it to any
person. Please contact us immediately to tell us that you have
received this e-mail, and return the original to us. Any use,
forwarding, printing or copying of this message is strictly prohibited.
No part of this message can be considered a request for goods or
services.
=======================================================================

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu