Patent ID: 7764111

Claim:
A CPU core voltage supply circuit comprising: a reference voltage generator outputting a first reference voltage and a second reference voltage; a control transistor having a first terminal receiving the first reference voltage; a differential operation amplifier having a positive input end, a negative input end and an output end, wherein the positive input end of the differential operation amplifier is connected to a second terminal of the control transistor; a power element having a receiving terminal and a current output terminal, wherein the receiving terminal of the power element is connected to the output end of the differential operation amplifier; a feedback circuit connected to the current output terminal of the power element and outputting a feedback voltage to the negative input end of the differential operation amplifier; a first capacitor having an end connected to the current output terminal of the power element and the other end receiving a first voltage, thereby providing a CPU core voltage; a load resistor having both ends respectively connected to a high voltage and the power element; and an over-current comparator having a reference input end receiving the second reference voltage and another two input ends respectively connected to the both ends of the load resistor for detecting a voltage drop across the load resistor, wherein the over-current comparator compares the voltage drop with the second reference voltage, and if the voltage drop is greater than the second reference voltage, the output end of the over-current comparator outputs an over-current signal to the control transistor so as to control transmission of the first reference voltage to the differential operation amplifier.