Who can provide ADS model for Class-D or G Audio power amplifier?

[tony_lth]

ADS has a example about Class-D amplifier, but that is direct freq amplifier, runing at 850MHz.
You can find that amplifier in ADS2011 example, about class-D and THD calculation.

But the live audio class-D amplifer has freq convertion, i.e. has a clock, say 1.6MHz, and the input audio signal is a modulated signal for amplifier.
And maybe use PWM to adjust power.

I tried to mix the audio signal with 1.6MHz, then pass ADS Class-D power amplifier, but the output audio power is very low, about -90dBm. I can upload my simulation tomorrow if anyone interests.

I would be very thankful for your help.

 

[mtwieg]

Your post isn't very clear about what you're trying to do. Keep in mind there are two completely different amplifier types called class D. One uses PWM to synthesize signals much lower than the carrier frequency (this is the type used in audio amps, but it is often called class-S by RF engineers) and the other is meant to synthesize RF at the carrier frequency (and there are voltage mode and current mode variations of this type).

Which type are you trying to analyze?

 

[tony_lth]

Hi, mtwieg,

I want to simulate the audio amps Class-D, i.e. class-S.
I found one Class-D in ADS, which I think is the second Class-D RF amp.

- - - Updated - - -

And, the attachment Class-D is originally designed for 850Mhz. For using it in audio, I have changed the C3/c4 from 1uF to 1000uF, and shorted SLC.
But it can't be used for audio. What else should I change? The Area is the last option to change, should I change it?
I think that I can't change this Rf class-D amp into audio one.
Can you post a sample for audio class-D? Many thanks.

 

[tony_lth]

Finally I built up a amp, but I don't know how to sweep Fmod.
The sch worked well at single point, but when I use ParamSweep to sweep the Fmod, all the results are changed.
I guessed there must be some different format on the calculation, could you help? Many thanks.

- - - Updated - - -

And, this is another equation.
What I mean is when I sweep Fmod, all the equations are invalid.

 

[mtwieg]

Hi, mtwieg,

I want to simulate the audio amps Class-D, i.e. class-S.
I found one Class-D in ADS, which I think is the second Class-D RF amp.

- - - Updated - - -

And, the attachment Class-D is originally designed for 850Mhz. For using it in audio, I have changed the C3/c4 from 1uF to 1000uF, and shorted SLC.
But it can't be used for audio. What else should I change? The Area is the last option to change, should I change it?
I think that I can't change this Rf class-D amp into audio one.
Can you post a sample for audio class-D? Many thanks.

A RF class D and an audio class S amp are completely different from each other, it makes no sense to try and modify one into the other. Class S audio amps are typically made using a half bridge output with MOSFETs.

 

[tony_lth]

Hi, mtwieg,

But my #4 post is a class -S audio amp. Yes, you are right, my orginal thought was wrong.