摘要 |
A reference supply voltage circuit includes a detecting device for detecting a first reference voltage, a comparator, and a preventing circuit for preventing any false operation during pre-operation indefinite time interval. The comparator outputs a signal which controls an operation circuit whose supply voltage is a second reference voltage equal to or lower than the first reference voltage. The preventing circuit maintains the second reference voltage to a circuit reference potential when the first reference voltage is lower than a first predetermined voltage, sets the second reference voltage to a voltage equal to the first reference voltage when the first reference voltage is equal to or higher than the first predetermined voltage and lower than a second predetermined voltage, and sets the second reference voltage to a voltage proportional to the first reference voltage when the first reference voltage is equal to or higher than the second predetermined voltage.
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