| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sensor drive device and a sensor drive system capable of forcibly shifting to a protective mode and informing an external device of a self-shift to the protective mode when abnormal conditions occur in self-operation surroundings. <P>SOLUTION: ASIC 70 performs a switch control depending on a current-conducting mode indicated by a microcomputer 60 and a current-conducting control of an all-region air/fuel ratio sensor 10. When decrease of battery voltage is detected by a power supply voltage comparison circuit 78 or when a hardware reset detection circuit 79 is informed about an implementation of hardware reset from the external device, the abnormal conditions in the self-operation surroundings are detected directly or indirectly. Then all switches SW1 to SW8 are turned off and current-conducting to the all-region air/fuel ratio sensor 10 is stopped by forcibly shifting to the protective mode. Furthermore, an information signal informing the shift to the protective mode is output in an initial synchronous communication with the microcomputer 60. <P>COPYRIGHT: (C)2010,JPO&INPIT |
