Oki Electric Industry Co., Ltd.

Oki Semiconductor Co., Ltd.

Ken Nozaki

Takashi Honda

A semiconductor integrated circuit device includes a power supply circuit that generates one or more internal supply voltages from an external supply voltage, and one or more functional circuits that operate on the one or more internal supply voltages. A step-down converter in the power supply circuit generates one or more stepped-down voltages from the external supply voltage. A control circuit in the power supply circuit compares the external supply voltage with a reference voltage and selects the internal supply voltages from among the external supply voltage and the stepped-down voltages according to the result of the comparison. The semiconductor integrated circuit device can accordingly operate on different external power supplies, and can continue to operate on battery power even if the battery voltage drops.

Semiconductor integrated circuit device and power supply circuit

A delay circuit includes an output circuit including first and second output elements. The first and second output elements are connected serially between a first power supply source and a second power supply source. The delay circuit further includes a delay element, which is coupled between a first input circuit and an output circuit to generate a first control signal that is delayed with respect to the input signal. The delay circuit still further includes a first node coupled between the delay element and one of the first and second output elements; and a second node, coupled to the other output elements to supply a second control signal having substantially no delay with respect to the input signal.

Growing community of inventors

Miyazaki, Japan

Ken Nozaki