Patent ID: 7049879
Filing Date: 2006-05-23
Classification: G05F

Abstract:
1. A power supply circuit comprising: an electric switching element placed in a power transmission path connecting an input terminal to which an input voltage is applied and an output terminal through which an output voltage is applied to a load connected to the output terminal; a voltage detecting circuit detecting the output voltage supplied through the output terminal; a reference-voltage producing circuit producing a reference voltage in accordance with a target voltage; a voltage control circuit controlling the electric switching element so that the detected output voltage tracks the reference voltage; a current detecting circuit detecting an output current supplied through the output terminal to the load; a limited-current-value setting circuit setting a limited value to the output current, the limited value increasing gradually over time during a rise of the output voltage up to the target voltage; and a current limiting circuit controlling the electric switching element to keep the detected output current at a current value less than or equal to the limited value during the rise of the output voltage up to the target voltage, the current limiting control having priority over an output voltage tracking control.