| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce ripple of boosting voltage without increasing a layout area of a boosting power source circuit by controlling clock supply operation based on boosting voltage of plural charge pump circuits to which clock signals of which phases are different respectively are supplied. SOLUTION: Plural charge pump circuits 2, 3, 4 inputs power source voltage Vcc synchronizing with clock signals P1, P2, P3 respectively, performs boosting operation, and outputs it to a common connection node Nout. A ring oscillator 5 supplies clock signals P1, P2, P3 having different phases respectively to the plural charge pump circuits 2, 3, 4. Also, a resistor voltage dividing circuit 7 and a comparing circuit 6 constitute a control circuit controlling operation in which clock signals P1, P2. P3 are supplied to the plural charge pump circuits 2, 3, 4 from the ring oscillator 5 based on boosting voltage formed by plural charge pump circuits 2, 3, 4.</p> |
