| 摘要 |
PROBLEM TO BE SOLVED: To provide a charge pump circuit which can make its semiconductor substrate not carry the potential of a negative electrode output terminal but carry grounding potential. SOLUTION: The charge pump circuit has a positive voltage generating circuit 210 for generating a positive voltage +2VDD twice as large as a power-supply voltage VDD and has a negative voltage generating circuit 220 for generating a negative voltage -2VDD inversely twice as large as the power supply voltage VDD. The positive voltage generating circuit 210 comprises a first boosting portion 211 so having MOS transistors T31-T34 and capacitors C31, C32 as to generate the positive voltage +2VDD by feeding the power-supply voltage VDD. The negative voltage generating circuit 220 comprises an inverting portion 221 so having MOS transistors T41-T44 and capacitors C41, C42 as to generate the negative voltage -VDD by feeding the power supply voltage VDD, and comprises a second boosting portion 222 so having MOS transistors T51-T54 and capacitors C51, C52 as to generate the negative voltage -2VDD by feeding the negative voltage -VDD from the inverting portion 221. The transistors T31, T33, T34 and T41 are p-channel type ones, and transistors T32, T42-T44 and T51-T54 are n-channel type ones. COPYRIGHT: (C)2005,JPO&NCIPI
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