| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative voltage detection circuit which is hardly affected by temperature variation and variations in manufacturing process and can detect negative voltages with higher precision. SOLUTION: The negative voltage detection circuit includes a circuit 37 for generating a reference current Iref, a resistive dividing circuit 38 having one end to which a negative voltage to be detected is applied and the other end to which a mirror current of the reference current is supplied, and a first comparator 32 for comparing a first voltage Vref corresponding to the reference current with a second voltage at the other end when a mirror current flows. The reference current generation circuit includes first and second circuit sections for generating third and fourth voltages having negative and positive temperature coefficients, respectively, based on a current supplied from a current mirror circuit, a third circuit section for generating the first voltage, and a second comparator 31 for controlling the current mirror circuit such that a voltage difference between the third voltage and the fourth voltage matches. COPYRIGHT: (C)2009,JPO&INPIT
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