Hi,
Did you see TAS5634?
I think it comes close to your requirements.
Klaus
No, it´s simply the result of clipping.what impressed me is that if you look at the THD versus power you see that it dramatically increases over 200W
Hi,
No, it´s simply the result of clipping.
Klaus
Some interesting links. Take some time, read the datasheets as well as the application notes and design notes.
https://www.infineon.com/cms/de/product/power/audio-driver-ics/class-d-audio-ics/#!products
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d462677d0f460167bba4f4e81abd
https://www.infineon.com/cms/de/product/power/audio-driver-ics/
https://www.microsemi.com/document-...-class-d-stereo-audio-amplifier-controller-ic
Klaus
Why do you think it is not commonly used?Still wondering why what I am proposing (directly driving the mosfets from digital circuits) is not commonly used.
Hi,
Why do you think it is not commonly used?
Many, many applications drive discrete halfbridges from digital circuits..
Or are you talking about audio Class D amplifiers in specific?
Klaus
I already agreed for audio amplifiers and additionally explained why...I think you should agree ..
I am talking about audio amplifiers only.
I think you should agree that it is not very common to drive the mosfets directly from a digital device.
To translate those amplitude numbers into PWM, you take the sine of the amplitude.
If you have novel requirements like this then you should probably provide more detail. Like what sort of pulse shape you want to create (you first mentioned 48Vrms, and then 150-160V....), required bandwidth, the load characteristics, how much ripple/distortion you can tolerate, etc. Off the shelf amplifiers designed for audio applications might not work for you (also note many of them are inherently AC coupled, which might also be a problem).However, I forgot to mention that the most important reason why I would like to develop it as a full-digital device is that for most of the time the device is silent. The most critical part is the recovery from the mute, which usually is not taken in consideration in commercial class D amplifiers as they are designed in order to output sound all the time, and not being switched on and off continuously. Using a FPGA would allow setting the output in high-Z when not transmitting. Of course there is the problem to do it pop-free.
The TAS5634 is quite slow in the recovery, too. Does this depend on charge pumps? Maybe this can be overcome with dc converters to power high side switches?
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