Mitsumi Electric Company Ltd.

Katsuhiro Yokoyama

Yoichi Takano

Shinichiro Maki

Disclosed is a power supply device including a first direct-current power source that generates a direct-current voltage to be supplied to a device that is a load, and a second direct-current power source that generates a direct-current voltage to be supplied to a sensor that detects a physical quantity. The first direct-current power source is an output variable type power source that generates a direct-current voltage that changes according to a signal from the sensor, and the second direct-current power source is an output fixed type power source that generates a constant direct-current voltage.

Power supply device and semiconductor device for power supply control

A power control semiconductor device includes a voltage control transistor, a control circuit, a bias circuit, and external terminals. The voltage control transistor is connected between a voltage input terminal and an output terminal. The bias circuit generates a voltage that operates the control circuit. Output control signals provided from an outside are input to the external terminals to control an output voltage. The control circuit includes an error amplifier and a logic circuit. The error amplifier outputs a voltage corresponding to a potential difference between a reference voltage and a voltage divided by a voltage divider that divides the output voltage. The logic circuit generates: a signal that changes the divided voltage in accordance with the output control signals; and a signal that stops operation of the bias circuit in response to a combination of the output control signals.

Power control semiconductor device and variable output voltage power supply

A power control semiconductor device includes: a voltage control transistor connected between an input terminal and an output terminal; a control circuit that controls the voltage control transistor in accordance with a voltage of the output terminal; and an external terminal that controls an output voltage externally. The control circuit includes: a first divider which has resistor elements connected in series to the output terminal and which divides the output voltage of the output terminal; a first error amplifier that outputs a voltage corresponding to a potential difference between a predetermined reference voltage and a voltage divided by the first divider; and an output voltage change circuit that changes the divided voltage in accordance with a voltage input to the external terminal to change the output voltage in accordance with the voltage of the external terminal.

Power control semiconductor device, variable output voltage power supply, and designing method

A power supply control apparatus includes a voltage control transistor connected between a DC voltage input terminal and an output terminal; a control circuit controlling the voltage control transistor according to an output feedback voltage; and a first external terminal receiving an output control signal to control an output voltage. The control circuit includes a first error amplifier outputting a voltage according to an electric potential difference between a voltage divided by a first voltage dividing circuit which divides the output voltage of the output terminal and a predetermined reference voltage; and an output changing circuit including a second error amplifier receiving a voltage input in the first external terminal, a transistor having a control terminal receiving the output of the second error amplifier, and a current mirror circuit connected to the voltage input terminal which transfers an electric current flowing in the transistor. The output changing circuit displaces the divided voltage according to a voltage input at the first external terminal to change the output voltage according to the output control signal.

Semiconductor apparatus for power supply control and output voltage variable power supply apparatus

A power supply control apparatus includes a voltage control transistor connected between a DC voltage input terminal and an output terminal; a control circuit which controls the voltage control transistor according to an output feedback voltage; and a first external terminal receiving an output control signal to control an output voltage. The control circuit includes a first error amplifier outputting a voltage according to an electric potential difference between a voltage divided by a first voltage dividing circuit which divides the output voltage of the output terminal and a predetermined reference voltage; and an output changing circuit including a second error amplifier receiving a voltage input in the first external terminal, a transistor having a control terminal receiving the output of the second error amplifier, and a current mirror circuit connected to the voltage input terminal which transfers an electric current flowing in the transistor. The current mirror circuit is connected to a node from which the divided voltage is taken out, and the output changing circuit displaces the divided voltage according to a voltage input in the first external terminal to change the output voltage according to the output control signal.

A semiconductor apparatus for power supply control includes the following. A voltage control transistor is connected between a voltage input terminal and an output terminal. A control circuit controls the voltage control transistor according to an output feedback voltage. A first external terminal is supplied with an output control signal to control output voltage is input. The control circuit further includes the following. A first error amplifier outputs a voltage according to an electric potential difference between a voltage divided by a first voltage dividing circuit which divides the output voltage of the output terminal and a predetermined reference voltage. An output changing circuit displaces the reference voltage input in the first error amplifier or the voltage divided by the first voltage dividing circuit according to a voltage input in the first external terminal to change the output voltage to a voltage according to the output control signal.

A semiconductor integrated circuit for a regulator includes an output controlling transistor, a controller circuit, a breeder resister and a current limiting resistor. The output controlling transistor is connected between an output terminal and a voltage input terminal. The breeder resister is connected between the output terminal and a constant potential point and generates the feedback voltage. The current limiting resistor is connected with the breeder resistor between the output terminal and the constant potential point.

Semiconductor integrated circuit for regulator

A semiconductor integrated circuit for a regulator includes an opening error detecting circuit detecting an opened state of an output terminal; a short-circuiting error detecting circuit detecting a short-circuiting state thereof; a first output terminal outputting a result detected by the opening error detecting circuit to an external unit; a second output terminal outputting a result detected by the short-circuiting error detecting circuit thereto; and a thermal shutdown circuit detecting the temperature of a semiconductor substrate and turns off the voltage control transistor if the detected temperature of the semiconductor substrate exceeds a predetermined temperature. A signal indicating the logic sum of an output signal of the thermal shutdown circuit and that of the short-circuiting error detecting circuit is outputted from the second output terminal such that the output signal of the opening error detecting circuit is not blocked based on the output signal of the thermal shutdown circuit.

A semiconductor integrated circuit includes a control transistor, a control circuit, a reference circuit, a current source, and a stabilizing circuit including a first transistor whose base is connected to a node to receive the reference voltage. The reference circuit includes series-connected second transistor and first and second resistors, third and fourth transistors and third and fourth resistors, and fifth and sixth transistors. The fifth transistor has connected base and collector, which base is connected to a base of the third transistor, the second transistor has a base connected to a node between third and fourth transistors, fourth and sixth transistors have bases connected to a first node between first and second resistors or a second node between second transistor and first resistor, a potential at the first or second node is the reference voltage, and a gain is determined depending on a resistance of the first resistor.

Clamp circuit to suppress reference voltage variation in a voltage regulator

A semiconductor integrated circuit for a regulator, including: a control transistor; a control circuit; and a discharge circuit, wherein the discharge circuit includes: a constant current source circuit; a reference voltage generating circuit; a voltage comparator circuit; and a current amplification circuit, and wherein the control circuit is configured to control the control transistor in response to the control signal, and the discharge circuit is configured to operate the discharge transistor by the amplified current amplified by the current amplification circuit.

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Atsugi, Japan

Katsuhiro Yokoyama