| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage converting circuit that guarantees to obtain a predetermined output voltage without relying on an initial value of an output voltage. SOLUTION: In this voltage converting circuit, when the detection signal of a voltage detection circuit 113 shows that the output voltage Vint has not reached a predetermined value, a selector circuit 105 outputs a ground level signal to a switching transistor circuit 107. Thereby, the switching transistor circuit 107 outputs an external voltage Vdd to a low-pass filter circuit 108. When the output voltage Vint that is outputted from an output terminal TT reaches a predetermined value, which makes a control circuit 101 operate normally, the voltage detection circuit 113 outputs to the selector circuit 105 a detection signal that represents that the output voltage Vint has reached the predetermined value. Then, the selector circuit 105 outputs to the switching transistor circuit 107 control signals SS1, SS2 boosted by first control signals CC1, CC2 from the control signal 101. COPYRIGHT: (C)2005,JPO&NCIPI
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