Hello audio amp experts,
I'm reviewing the "Switching Audio Power Amplifier" circuit example available through the Simscape product line. I'm new to amplifier design (and negative feedback control) so please bear with me.
The example shows an amplifier with the output signal being used as negative feedback to the modulator input (see Vo in 1st figure below). If we look inside the "Feedback Controller" (2nd figure below) we see that the "meas" output is fed directly into a subtract block without any feedback gain applied. Now, if we inspect the Vin/Vout waveforms we see that the output voltage "meas" tracks the input voltage "ref" (see 3rd figure below). My question is -- where is the amplification ? How come the output voltage is identical in amplitude and bias to the input voltage ?