Patent ID: 6903599

Claim:
A regulated charge pump comprising: a negative charge pump for generating a first output voltage by determining an oscillation signal; a regulator for restricting a swing of the first output voltage, the regulator comprising: a level shift circuit connected to the negative charge pump for generating a second output voltage at an output end of the level shift circuit by determining the first output voltage generated by the negative charge pump, the level shift circuit comprising: a plurality of serially connected PMOS transistors, a first source of a first PMOS transistor of the PMOS transistors connected to a first reference voltage source, a first gate and a first drain of the first PMOS transistor connected to the output end of the level shift circuit, and a second gate and a second drain of a second PMOS transistor of the PMOS transistors connected to the output end of the negative charge pump; a differential amplifier, whose first and second input ends are connected to a second reference voltage source and the output end of the level shift circuit respectively, for generating a compare signal by determining a voltage difference between the second output voltage and a voltage generated by the second voltage source; and a voltage-controlled oscillator connected between an output end of the differential amplifier and an input end of the negative charge pump; and a protection circuit, whose input end and output end are connected to the output end of the negative charge pump and wells of the PMOS transistors respectively, for generating a first protection voltage at the output end of the protection circuit by determining the first output voltage.