PWM is just one (very inexpensive) way to implement a DAC (digital to analog converter). Other methods actually set the output voltage to the target voltage, su

PWM is just one (very inexpensive) way to implement a DAC (digital to analog converter). Other methods actually set the output voltage to the target voltage, such as a R-2R ladder. I don't think R-2R ladders are used very much in practice anymore but I can't remember any other implementations off the top of my head.