WELL BIAS CONTROL CIRCUIT AND METHOD

摘要

PURPOSE: A well bias control circuit and method are provided to prevent the damage of a semiconductor chip by coping with the instantaneously change of external power voltage and to protect an interface circuit. CONSTITUTION: A transistor constitutes an interface circuit between first supply voltage and second supply voltage. A first control circuit(110) provides high voltage among the first supply voltage and the second supply voltage to an output node. A second control circuit(120) provides the high voltage among the first supply voltage and the second supply voltage to an output node. The second control circuit partly recompenses an operation of the first control circuit. A power source comparator(130) compares the VDDUSB of an USB port and VBATT of the battery power.