20080317105 | Low-current radio-frequency transceiver for use in short-range duplex communications applications - A low-current transceiver, powered by two small low-voltage batteries, for use in wireless headset/phoneset applications, such as hands-free headsets used with cellular telephones. Re-use of current from at least one circuit to provide power to at least one other power-consuming element of the transceiver, along with interrupt-driven control of the current made available to transmit and receive circuits, enables extended battery life (e.g., 120 hours). The headset/phoneset circuits incorporate a technique that draws an extremely low supply current from two low-voltage batteries while providing clear two-way communication over a range of about 3 meters. | 12-25-2008 |