| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a timer circuit using a capacitive element which can detect that a capacitive element therein has become shorted. <P>SOLUTION: The timer circuit includes a comparator CMP1 which, upon start of charging or discharging of a capacitive element, compares the potential of a capacitive element C and that of a reference voltage VREF_H which is higher than the potential of ground GDN and lower than that of a power supply VDD, and outputs a predetermined time-up signal when the potential of the capacitive element C has reached the potential of the reference voltage VREF_H; a control circuit which controls the potential of the capacitive element C so that it will be higher than the potential of ground GND and higher than that of a reference voltage VREF_S which is lower than the potential of the reference voltage VREF_H; and a comparator CMP2 which compares the potential of the capacitive element C and that of the reference voltage VREF_S, and, if the potential of the capacitive element C drops below that of the reference voltage VREF_S, outputs a shorting detected signal notifying that a shorted state of the capacitive element has been detected. <P>COPYRIGHT: (C)2012,JPO&INPIT |
