Portable identification transmitter i.e. electronic key, for motor car, has microcontroller generating wake-up signal to activate high frequency-transmission and reception circuits and communicating with motor car-side control-device

摘要

The transmitter (1) has a passive position or motion sensor (17) generating a sensor signal in a microcontroller (4) when detecting a position or motion of the transmitter. The microcontroller generates the sensor signal in a power-saving rest mode. The microcontroller outputs an output signal controlling a power supply of low frequency (LF)-reception circuits (6, 7) to activate the LF-reception circuits. The microcontroller generates a wake-up signal to activate high frequency-transmission and reception circuits (5), and communicates with a motor car-side control-device. An independent claim is also included for a method for power-saving operation of a portable identification transmitter.