| 摘要 |
PURPOSE: A voltage boosting circuit is provided to prevent a deterioration of an operation characteristic by providing a power-supply voltage by using PMOS transistor. CONSTITUTION: A voltage boosting circuit includes a power-supply voltage detector(10), NAND gate, a delay part(20), first and second inverters(INV1,INV2), first and second power output parts(110,120), a first capacitor(C1), a second capacitor(C2), NMOS transistor(NM3), NMOS transistors(NM4,NM5). The power-supply voltage detector(10) detects a level of a power-supply voltage(Vcc). NAND gate performs NAND operation about an output signal(VDS) and clock signal(CLK) of the detector(10). The delay part(20) delays an output signal of the NAND gate by a predetermined time(d). The inverters(INV1,INV2) invert an output signal of the delay part(20) and a clock signal of the delay part(20). The power-supply output parts(110,120) output a power-supply voltage(Vcc) by an output signal of the second inverter(INV2). The first capacitor(C1) boosts a voltage by means of the voltage(Vcc) of the first power-supply output part(110). and the clock signal(CLK). The second capacitor(C2) boosts a voltage by means of the voltage(Vcc) of the second power-supply output part(120). The NMOS transistor(NM3) commonly connects gate and drain, and outputs a voltage of the first node(N1) to a second node(N2) of a source. The NMOS transistors(NM4,NM5) output a voltage of the first and second nodes(N1.N2) to an output terminal(OUT) of source. Thereby, a deterioration of an operation characteristic is prevented by providing a power-supply voltage by using PMOS transistor.
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