Hi,
I'm designing a simple class D audio amplifier at the moment, and have been reading up on what each section of the amplifier does. As I understand it, the low-pass filter at the last section of the circuit design changes the PWM square-wave signal into a smooth sinusoidal signal again. What I don't understand is how it does that? I was under the impression that all filters did was to allow/block waves with past a threshold frequency which depends on whether it is a high-pass, low-pass or band-pass filter. And does the filter play any other roles in this amplifier?
Any help there would be appreciated. Thanks in advance.
I'm designing a simple class D audio amplifier at the moment, and have been reading up on what each section of the amplifier does. As I understand it, the low-pass filter at the last section of the circuit design changes the PWM square-wave signal into a smooth sinusoidal signal again. What I don't understand is how it does that? I was under the impression that all filters did was to allow/block waves with past a threshold frequency which depends on whether it is a high-pass, low-pass or band-pass filter. And does the filter play any other roles in this amplifier?
Any help there would be appreciated. Thanks in advance.