Ricoh Company, Ltd.

Ricoh Electronic Devices Co., Ltd.

Masashi Oshima

Masaya Ohtsuka

Kuniaki Arai

Junichi Kanno

Ryuta Isobe

Provided is a protective semiconductor device detecting a disconnection reliably with secondary cells including for each cell: cell-connecting terminals; a first resistance detecting the voltage of each cell; a comparator detecting whether or not the voltage of each cell is in the reference voltage range; a series circuit composed of a second resistance and a first switch element, and including a control circuit controlling ON/OFF of the switch element, wherein the first switch element connects the second resistance to the connecting terminals by turning ON, while disconnecting it by turning OFF, the control circuit maintains a disconnection test signal ON, while turning ON the plurality of first switch elements sequentially and detecting the disconnection between the cells and the connecting terminals based on the output signal from the comparator corresponding to the first switch element turned ON.

Protective semiconductor device for secondary cell

A signal transmitting-receiving circuit includes a first circuit including a first MOS transistor having a gate and a drain, a second MOS transistor having a gate and a drain connected to the gate and drain of the first MOS transistor, and a source connected to ground, and a transmitting terminal transmitting a signal connected to the drains of the first and second MOS transistors; and a second circuit including a receiving terminal receiving the signal transmitted from the transmitting terminal of the first circuit connected to the transmitting terminal, a third MOS transistor having a gate connected to the receiving terminal, a drain connected to a reference voltage generator circuit and a source connected to ground, a resistor connected between the third MOS transistor and the reference voltage generator circuit, and an output terminal connected between the resistor and the third MOS transistor.

Signal transmitting-receiving control circuit and secondary battery protection circuit

A semiconductor device includes a semiconductor substrate, a base insulating layer, a silicon fuse, a pair of silicon wires, a silicon guard ring, an insulation coating, a first interlayer insulating layer, a via guard ring, a metal guard ring, a final insulating layer, and a fuse window. The base insulating layer is disposed over the semiconductor substrate. The silicon fuse is disposed on the base insulating layer. The pair of silicon wires is disposed on the base insulating layer. The silicon guard ring is disposed on the base insulating layer. The insulation coating is deposited at least over surfaces of the silicon wires. The first interlayer insulating layer is disposed on the base insulating layer. The final insulating layer is disposed on the interlayer insulating layer. The fuse window is defined above the silicon fuse inside the guard rings.

Semiconductor device with a fuse

A semiconductor device includes a base insulating film on which a silicon fuse, silicon wiring patterns, and a silicon guard ring are formed. The silicon guard ring surrounds the silicon fuse and has silicon cutout parts so as not to contact the silicon wiring patterns. A via guard ring, which has via cutout parts located above the silicon cutout parts, is formed in an interlayer insulating film and on the silicon guard ring. A metal wiring guard ring is formed on the via guard ring and the interlayer insulating film. A silicon nitride film is formed on the interlayer insulating film so as to cover the metal wiring guard ring. An interface between the interlayer insulating film and the metal wiring guard ring at the via cutout parts is covered by the silicon nitride film.

Growing community of inventors

Kanagawa, Japan

Masashi Oshima