| 摘要 |
PROBLEM TO BE SOLVED: To reduce EMI noise corresponding to a frequency of a clock signal which activates a charge pump.SOLUTION: A semiconductor device comprises: a charge pump 10 which generates booster voltage VOUT having the same polarity or a reverse polarity with input voltage by an operation according to a clock signal PUMPCLK; an oscillation circuit 20 which generates and outputs the clock signal PUMPCLK. The oscillation circuit 20 periodically varies the frequency of the clock signal PUMPCLK within a predetermined variation range.SELECTED DRAWING: Figure 1 |
