摘要 |
A power supply voltage regulator circuit including a power supply circuit which switches to a first through a fourth state; the first state being the state wherein voltage is supplied to neither a normal circuit nor a backup system circuit based on the combination of logic for the normal circuit power control signal, the second state being the state wherein a primary power supply voltage is supplied to the normal circuit and a secondary power supply voltage is supplied to the backup system circuit, the third state being the state wherein voltage is not supplied to the normal circuit and the secondary power supply voltage is supplied to the backup system circuit, the fourth state being the state wherein the primary power supply voltage is supplied to both the normal circuit and the backup system circuit.
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