| 摘要 |
A compact watch dog timer circuit which includes a pulse period determining circuit (1) for generating a timer reset pulse if a period of an input pulse from an external machine falls within a tolerance range or beyond an upper limit of the tolerance range and no timer reset pulse if the period falls below a lower limit of the tolerance range; and a timer (2) for generating a signal for restoring the external machine to a predetermined condition when no timer reset pulse is fed from the pulse period determining circuit within a timer period which is set corresponding to the tolerance range. |
