A 6×5×4mm 3 general purpose audio sensor node with a 4.7μW audio processing IC

We present a complete, fully functional energy-autonomous audio sensor node with 6×5×4mm 3 form factor. The system uses a new audio processing IC integrated with a MEMS microphone, general purpose 32-bit processor, 8Mb Flash, RF transceiver with custom 3D antenna, PV cells for energy harvesting and battery. The 4.7μW audio processing IC performs audio acquisition with 4–32× compression. The complete stand-alone system achieves 38mins of speech recording and energy-autonomous operation in room light.