ELECTRONIC DEVICE COMPRISING AN OPERATING MODE SWITCHING UNIT

摘要

An electronic appliance comprising an electrical circuit and an operating mode switching unit which can be awakened out of a sleep state into a working state in which the current consumption of the circuit is greater in than in the sleep state. To receive a radio signal, the appliance has a receiver comprising a UHF carrier that is amplitude-modulated by a modulation signal. The receiver comprises a UHF antenna connected to a passive filter stage to an input of a passive rectifier circuit. An output of the rectifier circuit is connected to a detector for the modulation signal. To wake the electrical circuit from the sleep state, the operating mode switching unit has a control connection to the detector. The appliance has a low current draw in the sleep state by matching the output impedance of the rectifier circuit to the input impedance of the detector.