Patent ID: 8957652
Filing Date: 2015-02-17
Classification: H03K,H05B,Y02B

Abstract:
1. An output circuit for supplying an output current to a load coupled to an output terminal in response to an input signal, said output circuit comprising: an output transistor supplying the output current to the output terminal; an output-drive circuit driving the output transistor; a current limiting circuit generating a current control signal for limiting the output current to a predetermined current value; and a control circuit implementing a control such that the output current is controlled on a basis of the current control signal if a voltage at the output terminal is at a predetermined voltage value or less after the input signal is supplied while the output transistor is driven by the output-drive circuit if the voltage at the output terminal is in excess of the predetermined voltage value, wherein the control circuit includes a switch circuit coupled between a control terminal of the output transistor, and the current limiting circuit, and wherein the switch circuit is turned ON in response to the input signal while the switch circuit is turned OFF in response to a result of comparison of the voltage at the output terminal with a first reference voltage, wherein the switch circuit is controlled in response to a first control signal, wherein the control circuit further comprises a first output-voltage comparison circuit, and a drive-control circuit, wherein the first output-voltage comparison circuit compares the voltage at the output terminal with the first reference voltage, outputting a comparison result as a second control signal, and wherein the drive-control circuit outputs the first control signal in response to the input signal and the second control signal.