ON-VEHICULAR DEVICE AND ITS POWER SOURCE CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To reduce unnecessary consumption of a battery power source by shutting off feeding of power source to CPU and devices at the periphery at high speed when a key of a vehicle is turned OFF.

SOLUTION: The on-vehicular device is provided with a power source circuit 2; a micro-computer 18 for directly receiving feeding of power source from the power source circuit 2; a first power source switch circuit 15 connected to the power source circuit 2; the CPU 10 and a power source control circuit 32 for receiving feeding of power source through the first switch circuit 15; a second switch circuit 30 connected to a power source line at an output side of the first power source switch circuit 15; and the devices 11-13 at the periphery of CPU for receiving feeding of power source through the second switch circuit 30. The micro-computer 18 detects that the key of the vehicle is turned OFF and transfers the CPU 10 to a low power consumption mode. The power source control circuit 32 detects that the CPU 10 is transferred to the low power consumption mode and shuts off feeding of power source to the devices 11-13 at the periphery of the CPU by controlling the second switch circuit 30.

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