| 摘要 |
PURPOSE: A memory backup device and a method in a smart phone are provided to supply power to an SDRAM only during a memory backup process, by using a self-refresh function of the SDRAM, and to cut off power in a CPU and peripheral circuits, thereby reducing power consumption. CONSTITUTION: A power checking unit(208) checks whether a power supplied from a main power supplier(204) is less than an operational voltage. If so, a backup power switching unit(210) cuts off the power supplied from the main power supplier(204), and switches such that a backup power is supplied from a backup battery(207). A backup power supplier(206) includes the backup battery(207) for supplying the backup power and a DC-DC converter(211) for boosting a voltage outputted from the backup battery(207) and outputting the boosted voltage to a memory backup circuit(212). The memory backup circuit(212) receives the voltage to apply a high signal to a chip selector terminal of a nonvolatile memory(202), and supplies the operational voltage to a power terminal of the memory(202).
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