Figure 1b shows a variation of thiscircuit. Using the switch node formerlygrounded as an additional analoginput produces a circuit that gives anoutput equal to (A×D)+ (B× (1–D)).The PWM duty cycle ...

The PWM signal will be very robust to noise since it is either a 0 or a 1 instead of a small analog voltage. A class-D amplifier is a very inexpensive way to convert analog to PWM. A class-D amplifier ...