| 摘要 |
PROBLEM TO BE SOLVED: To provide a power-on detecting circuit which reduces power consumption and detects a rise of an input voltage with accuracy by a simple circuit. SOLUTION: The power-on detecting circuit PD1 includes a voltage converting circuit CNV1 to convert the input voltage to a current and a latch circuit LCH1 to maintain a detection signal of power-on. Output currents of the voltage converting circuit CNV1 are supplied to a current source I1 and a capacity C1 through a connection node ND11. The current source I1 supplies a current proportional to an absolute temperature. In the case that the output current of the voltage converting circuit CNV1 becomes larger than the current of the current source I1, the capacity C1 is charged and the connection node ND11 is pulled up. Then, the latch circuit LCH1 is turned on according to the voltage of the connection node ND11 and the detection signal of the power-on is outputted. COPYRIGHT: (C)2008,JPO&INPIT
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