Hi Kartino.
Given it is fixed frequency triangle wave with post filter feedback I threw something simple together in LTSpice.
Your triangle wave may not be the most linear of things but I calculate that it is 3.33V peak to peak. I assume your bridge supply is +/-100 because you have no fear.
As the input from your comparator moves from -1.67V to +1.67V your output voltage will move from -200 to + 200. This gives the gain of your power stage as 400/3.33 or 120.
Your feedback amplifier gain is set to 330/27K modified by its 4K7 output resistor and loaded by the resistors to the DC servo and buffer amplifiers. The first picture shows the model and the loop gain with an 8R load. The second picture shows the result unloaded.
There is in effect no excess loop gain to provide error correction but it is possible for the loop/amplifier to become unstable unloaded.
I'll try to throw together a switching model.
Given it is fixed frequency triangle wave with post filter feedback I threw something simple together in LTSpice.
Your triangle wave may not be the most linear of things but I calculate that it is 3.33V peak to peak. I assume your bridge supply is +/-100 because you have no fear.
As the input from your comparator moves from -1.67V to +1.67V your output voltage will move from -200 to + 200. This gives the gain of your power stage as 400/3.33 or 120.
Your feedback amplifier gain is set to 330/27K modified by its 4K7 output resistor and loaded by the resistors to the DC servo and buffer amplifiers. The first picture shows the model and the loop gain with an 8R load. The second picture shows the result unloaded.
There is in effect no excess loop gain to provide error correction but it is possible for the loop/amplifier to become unstable unloaded.
I'll try to throw together a switching model.
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Great, but can you explain the benefit your Class BD compare to your Xlite fullbridge ?
Audible improvemt is sound V/s Xlite ?
google wiki show BD = filterless Class D.....
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