| 摘要 |
A charge pump circuit is provided to prevent a parasitic bipolar transistor from being turned on during the operation of positive potential generation charge pump circuit by clamping the potential of a semiconductor substrate using a clamping diode. A positive potential generation charge pump circuit(1) generates a positive potential. A negative potential generation charge pump circuit(2) generates a negative potential. The negative potential is applied to a P type semiconductor substrate. A control circuit(3) controls the operation of the negative potential generation charge pump circuit and the positive potential generation charge pump circuit. An N type well is formed on the surface of the semiconductor substrate, and the positive potential is applied to the N type well. An N type diffusion layer is formed on the surface of the semiconductor substrate. A clamping diode clamps the potential of the semiconductor substrate in order to prevent a forward current from flowing to the diffusion layer from the semiconductor substrate.
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