| 摘要 |
PURPOSE: To achieve a battery protection and a sleep synchronous control efficiently at a low cost in a battery-driven device. CONSTITUTION: A power management circuit 10 for a battery-driven device is designed, such that sleeps is induced during a predetermined period when the device is not used, has an oscillator 12 for generating a clock signal, and has a battery monitor sub-circuit 14 for indicating when a predetermined low battery power state is reached, which includes a sub-circuit that allows the oscillator to generate a clock signal and a sub-circuit that responds to an instruction that the predetermined low battery state has been reached from a battery monitor sub-circuit. The sub-circuit interrupts the operation of the sub-circuit, that allows the oscillator to generate a clock signal. |
