Charge pump with reduced noise spikes

Abstract

A voltage supply circuit which suppresses generation of current spikes in the power source current in operation, reduce noise, simplify the circuit configuration, and decrease the cost. Clock signal CLK at a prescribed frequency is supplied to charge pump driver (); current sources ISIS, . . . ISwork at timing set with clock signal CLK to output driving currents; and, corresponding to the driving currents, capacitors C, C. . . are alternately charged or discharged; the charge stored in the capacitor of a preceding stage is sequentially sent to the later capacitor stage, and a boosted voltage higher than power source voltage Vcc is obtained at output terminal T. In the charge pump type booster, since capacitors are driven with current sources, it is possible to reduce spike noise in the boosting operation, and influence on other analog circuits can be suppressed.