Rohm Co., Ltd.

Takuya Okubo

Ko Takemura

Masaru Sakai

Koh Takemura

A power supply circuit relating to the present invention comprises a differential amplifier for feeding out a voltage as a control voltage in accordance with a difference between a feedback voltage commensurate with an output voltage and a reference voltage, an output current control element for feeding out an output current in accordance with the control voltage fed thereto from the differential amplifier, an output line by way of which the output current is supplied to a load, a feedback line by way of which a voltage on the output line is fed back as the feedback voltage to the differential amplifier, the feedback line connected to the output line, and a sink current generating circuit, connected between the feedback line and ground, for generating a sink current by which the control voltage fed to the output current control element is raised to a predetermined value.

Power supply circuit

A power supply circuit relating to the present invention comprises a differential amplifier for feeding out a voltage as a control voltage in accordance with a difference between a feedback voltage commensurate with an output voltage and a reference voltage, an output current control element for feeding out an output current in accordance with the control voltage fed thereto from the differential amplifier, an output line by way of which the output current is supplied to a load, a feedback line by way of which a voltage on the output line is fed back as the feedback voltage to the differential amplifier, the feedback line connected to the output line, and a clamping circuit for maintaining the control voltage so as not drop below a predetermined value.

The present invention provides a power supply device which can suppress a voltage drop of the input power supply immediately after recovery from shutdown status. The power supply device comprises a reference voltage generation circuit for generating reference voltage (VREF), a transistor for feeding disposed between an input terminal (VTT_IN) and an output terminal (VTT output terminal), a transistor for discharging disposed between a ground potential and a VTT output terminal, a first and second differential amplification circuits for controlling the transistors for feeding and discharging respectively by inputting the output power supply voltage (VTT) as feedback and comparing it with VREF, and a shutdown recovery circuit for generating voltage that gradually starts up by a constant current source and a capacitor, wherein the first differential amplification circuit compares VTT with the voltage (SR) of the shutdown recovery circuit instead of VREF, for a certain period from the point of recovery from shutdown status.

Power supply device and electronic equipment comprising same

A semiconductor integrated circuit comprises a semiconductor substrate, a heat-producing circuit element formed in a multi-layer structure on the semiconductor substrate and performing a predetermined operation while producing heat of a relatively high temperature, a plurality of temperature-dependent circuit elements, each formed in a multi-layer structure in a predetermined location on the semiconductor substrate, performing a predetermined operation depending on temperature of the heat-producing circuit element, and each having a constant relationship in temperature-related properties with each another, and a heat conductive layer having a heat conductivity higher than a heat conductivity of the semiconductor substrate, and covering at least a heat-producing portion of the heat-producing circuit element and the plurality of temperature-dependent circuit elements continuously so as to conduct the heat produced by the heat-producing circuit element to the plurality of temperature-dependent circuit elements. With this structure, the semiconductor integrated circuit can maintain its intended operating accuracy regardless of changes in temperature.

Semiconductor integrated circuit

According to the conventional stabilized DC power supply device, there is a possibility that the output transistor breaks down by heat when the input voltage fluctuates. To cope with this, the stabilized DC power supply device embodying the invention is so configured as to comprise an output transistor for converting an input voltage to an output voltage and feeding out the output voltage, a control circuit for controlling the output transistor so as to maintain a value of the output voltage constant, a current detection circuit for detecting an output current of the output transistor, a voltage detection circuit for detecting a voltage appearing between an input side and an output side of the output transistor, a multiplying circuit for multiplying an output of the current detection circuit and an output of the voltage detection circuit together, and a protection circuit for restricting a wattage power of the output transistor according to an output of the multiplying circuit.

Growing community of inventors

Kyoto, Japan

Takuya Okubo