Seiko Instruments Inc

Ablic Inc.

Sii Semiconductor Corporation

Daiki Endo

Yotaro Nihei

Socheat Heng

Fumimasa Azuma

A voltage detector includes a voltage division circuit which outputs a divided voltage based on an input voltage, a comparison circuit which compares the divided voltage and a reference voltage to output a detection signal and a release signal, and a voltage limiting circuit which limits the divided voltage to a preset voltage.

Voltage detector

To provide a voltage regulator equipped with an overcurrent protection circuit which needs not to separately adjust a limited current and a short-circuited current and is capable of collectively adjusting them. There is provided an overcurrent protection circuit equipped with an output current limitation circuit which distributes a current supplied from a transistor sensing an output current of an output transistor and controls a gate voltage of the output transistor by the distributed current to limit the output current. The overcurrent protection circuit is configured in such a manner that the current distributed from the transistor sensing the output current is varied according to the voltage outputted from the output transistor, and its distribution ratio is determined by a size ratio between elements.

Voltage regulator equipped with an overcurrent protection circuit capable of adjusting a limited current and a short-circuited current

To provide an overheat protection circuit which is not affected by a leak current while being low in current consumption and good in detection accuracy, and a voltage regulator equipped with the overheat protection circuit. An overheat protection circuit is configured to include a leak current detection circuit which detects that a leak current has flowed at a high temperature, a bias circuit which allows a bias current to flow in response to an output signal of the leak current detection circuit, and a temperature detection circuit operated by the bias current.

Overheat protection circuit and voltage regulator

There is provided a voltage regulator equipped with a reverse-current prevention function capable of ensuring safe performance without causing a large overshoot at an output terminal against a sharp fluctuation in source voltage. The voltage regulator provides a source voltage fluctuation detecting circuit for detecting a fluctuation in source voltage in a comparison circuit for comparing the source voltage with output voltage so that when the source voltage rises sharply, the current through constant current circuits for limiting the consumption current of the comparison circuit will be increased to improve the response characteristics.

Voltage regulator with improved reverse current protection

A voltage regulator has a phase compensation circuit which changes consumption current according to load current thereby to reduce consumption current. The phase compensation circuit includes: a first transistor having a drain connected to an output terminal of an error amplifier circuit; a second transistor having a drain connected to a gate of the first transistor and a gate connected to the gate of the first transistor; a current mirror circuit connected to the output terminal of the error amplifier circuit, a drain of the first transistor, and the drain of the second transistor; and a capacitor connected between the gate of the second transistor and a drain of an output transistor. Thereby, current consumed by the phase compensation circuit can be changed according to the load current, resulting in that the voltage regulator consumes less current.

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Chiba, Japan

Daiki Endo