| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reduced-voltage protective circuit which can ensure reduced-voltage protection even when precipitous and substantial reduction occurs in power supply voltage, and a switch driving device using such a reduced-voltage protective circuit. <P>SOLUTION: A reduced-voltage protective circuit 32 comprises: a first voltage monitoring unit 321 for monitoring whether a power supply voltage VCC is less than a first threshold voltage Vth1, and generates a first reduced-voltage protective signal S1; a second voltage monitoring unit 322 for monitoring whether the power supply voltage VCC is less than a second threshold voltage Vth2 lower than the first threshold voltage Vth1, and generates a second reduced-voltage protective signal S2; a filtering unit 323 for switching the first reduced-voltage protective signal S1 from a normal logic level to an abnormal logic level when a state where the power supply voltage VCC is less than the first threshold voltage Vth1 continues for a predetermined mask period Tm; and a logic gate 324 for generating a third reduced-voltage protective signal S3 based on the first reduced-voltage protective signal S1 and the second reduced-voltage protective signal S2. <P>COPYRIGHT: (C)2012,JPO&INPIT |
