| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that elements (capacitance element and charge transfer element) constituting a charge pump circuit deteriorate by residual electric charge and a problem of a malfunction resulting from the residual electric charge. <P>SOLUTION: N-channel type charge transfer MOS transistors T<SB>0</SB>to T<SB>M</SB>with short-circuited gate and drain are connected in series between an input terminal IN and an output terminal OUT. One-side terminals of capacitative elements C<SB>1</SB>to C<SB>M</SB>are connected to connection points (nodes A to X) of the respective charge transfer MOS transistors. The nodes A to X are connected to a voltage step-down circuit 30 through N-channel type MOS transistors N<SB>1</SB>to N<SB>M</SB>with short-circuited gate and source. Namely, when a boosting operation of the charge pump circuit is ended, a path is formed, which positively escapes the residual charge from the nodes A to X to the outside. <P>COPYRIGHT: (C)2008,JPO&INPIT |
