A low power microphone circuit for a vehicle is provided that includes: at least one microphone transducer; a digital signal processor for receiving output signals from the at least one microphone transducer and for generating a digitally processed audio signal; an output amplifier for amplifying the audio signal from the digital signal processor and modulating an input voltage with the audio signal; and a DC power supply for supplying power to the digital signal processor. The output amplifier and the DC power supply may be electrically coupled in series. The DC power supply and the output amplifier may be powered by the input current, where the input current is no greater than about 6 mA.