| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To maintain capacity of a backup power supply in a communication device which is connected to a power supply or the backup power supply and communicates in conformity to a CAN protocol. <P>SOLUTION: An air bag device 1 is equipped with a battery 2, a boosting circuit 3, the backup power supply 4, a microcomputer 7, and an air bag controlling IC 5. The air bag controlling IC 5 comprises: a power supply disconnection detection circuit part 52; a mode switching circuit part 53; and a CAN transceiver circuit part 54. When the boosting circuit 3 is interrupted, the power supply disconnection detection circuit part 52 outputs an STDBY0 signal, and the mode switching circuit part 53 outputs a mode switching signal. When the mode switching signal is inputted, the CAN transceiver circuit part 54 is switched in a standby mode with low power consumption. Accordingly, power consumption of the CAN transceiver circuit part 54 is suppressed during backup. Thus, the capacity of the backup power supply 4 is maintained. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
