Low power microphone circuits for vehicles

摘要

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.

主权项

1. A low power microphone circuit for a vehicle, comprising:
at least one microphone transducer; a digital signal processor for receiving output signals from said at least one microphone transducer and for generating a digitally processed audio signal; an output amplifier for amplifying the audio signal from said digital signal processor and modulating an input voltage with the audio signal; and a DC power supply separate from the output amplifier for supplying power to said digital signal processor; said at least one microphone includes a first microphone transducer and a second microphone transducer; said digital signal processor processes output signals from said first and second microphone transducers to produce a first audio signal, wherein said output amplifier amplifies the first audio signal by modulating a first input voltage; the low power microphone circuit further comprising: a first terminal for connection to a vehicle power source providing the first input voltage and a first input current, said first terminal coupled to said output amplifier; a second terminal for connection to the vehicle power source providing a second input voltage and a second input current; and a second output amplifier coupled to said second terminal, wherein said output amplifier and said DC power supply are electrically coupled in series.