| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage conversion circuit wherein the rise time can be shortened and adjusted when it is started and its undershoot characteristics are improved. SOLUTION: An output from a charge pump circuit 20 is converted into a digital data through an A-D converter 32, and this converted data and reference voltage are subjected to subtraction at a subtractor 33. A mode signal is generated at a decoder 34 according to the result of subtraction. The rate of change of a counter 11 is varied according to this mode, and the voltage of the charge pump circuit 20 is set according to this variation. Accordingly, the rise time of the voltage conversion circuit is shortened and adjusted when it is started and undershoot is prevented. COPYRIGHT: (C)2006,JPO&NCIPI
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