Brother Industries, Ltd.

Rohm Co., Ltd.

Akira Fujiwara

Yukihiko Sato

Masanori Oda

Nobuyoshi Ueyama

Masakazu Nagata

Takashi Kimura

A system power supply circuit receives an input voltage V, and supplies a power supply voltage to multiple load circuits including a microcomputer. Multiple power supply circuits support the multiple load circuits. An abnormality detection circuit generates an abnormality detection signal that is negated when the input voltage Vis within, and asserted when it deviates from, the first voltage range, and outputs this signal to the microcomputer. The interface circuit can communicate with the microcomputer. The interface circuit receives a control signal generated by the microcomputer in response to abnormality detection signal assertion, and suspends power supply circuit operation of a channel indicated by the control signal. When the input voltage Vdeviates from a second voltage range defined to be wider than the first voltage range, an internal protection circuit suspends at least one power supply circuit of a predetermined channel.

System power supply circuit

A regulator circuit includes: a regulator part configured to generate a constant internal power supply voltage based on an external power supply voltage; a connection port configured to receive power from the regulator part and to be connected to a connection cable having a predetermined cable resistance, the connection cable is configured to electrically connect the connection port to an external device; a current detecting part configured to detect a power supply current when the connection cable is connected to the connection port; and a voltage compensation part configured to compensate a voltage corresponding to a voltage drop due to the cable resistance according to a current value detected by the current detecting part.

Charging device including regulator circuit and integrated circuit

Graphic user interface for handheld terminal

Growing community of inventors

Kyoto, Japan

Akira Fujiwara