| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a circuit for a charge pump by which low power consumption is attained. <P>SOLUTION: A first clock signal Φ is supplied from an oscillation circuit 10 to capacitative elements C<SB>1</SB>-C<SB>M</SB>constituting the circuit for the charge pump. A current generation circuit 30 controls current I supplied to the respective inverters 21a-21x by controlling operations of PMOSs 25a-25x and NMOSs 24a-26x and as a result, performs frequency control of the first clock signal Φ. A gate and a drain of a PMOS 31 are short-circuited, a constant current generation circuit 34 and a resistor 35 are connected in parallel between a connection point and a grounding terminal GND. The constant current generation circuit 34 acts so as to maintain the current I supplied to the inverters 21a-21x as constant to change of power supply voltage. Thus, a frequency f<SB>Φ</SB>of the clock signal Φ decreases against increase in the power supply voltage VCC. <P>COPYRIGHT: (C)2008,JPO&INPIT |
