Rohm Co., Ltd.

Kimio Ando

Isao Yamamoto

Shigekane Matsui

Yuki Aoki

A detection circuit is mounted on an electronic device having a communication function, including at least a battery, a CPU, and a communication unit, and is configured to detect the remaining battery charge. An A/D converter performs sampling of a magnitude of a current Idischarged from the battery, and converts the current Ithus sampled into a digital current value. An interface circuit receives, from the CPU, control data which indicates a period in which there is an increase in the current discharged from the battery. Based upon the control data, a control unit raises the sampling frequency of the A/D converter in the period in which there is an increase in the current I.

Battery fuel gauge circuit

A multiplexer receives multiple differential signals, selects one differential signal, and outputs, via an output port, the differential signal thus selected. The multiple differential signals are respectively input to multiple differential input ports. Multiple buffers are respectively provided to the multiple differential input ports. Each buffer includes a differential input terminal connected to a corresponding differential input port, and a differential output terminal connected to an output port. Each buffer is configured to be capable of switching states, according to the control signal, between an enable state in which a differential signal that corresponds to a differential signal input to the differential input terminal is output, and a disable state in which current consumed by the buffer becomes substantially zero, and the differential output terminal thereof is set to a high-impedance state.

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Kyoto, Japan

Kimio Ando