Patent ID: 8847569
Filing Date: 2014-09-30
Classification: G05F

Abstract:
1. A semiconductor integrated circuit for a regulator, comprising: a controlling transistor connected between an input terminal and an output terminal; a current detection circuit that detects an output current flown from the controlling transistor and outputs a detection voltage proportional to the output current; a feedback voltage generation circuit that generates a feedback voltage proportional to an output voltage in a reduction manner; and a control circuit that controls the controlling transistor so that the output voltage is constant in response to the feedback voltage, wherein the control circuit includes: a first circuit that receives the detection voltage and the feedback voltage, functions as a comparator during a period in which the output current is higher than a predetermined value, and functions as a buffer that outputs a voltage proportional to the feedback voltage during a period in which the output current is lower than the predetermined value; a second circuit that receives a voltage serving as a reference, the feedback voltage, and the voltage outputted from the first circuit, generates a voltage corresponding to a potential difference between the feedback voltage and the output voltage of the first circuit during a period in which the voltage serving as the reference is lower than the voltage outputted from first circuit, and when the voltage serving as the reference becomes higher than the voltage outputted from the first circuit, generates a voltage corresponding to a potential difference between the feedback voltage and the voltage serving as the reference, and supplies the generated voltage to a control terminal of the controlling transistor; and a current restricting transistor provided between the input terminal and the control terminal of the controlling transistor and controlled by the voltage outputted from the first circuit.