Mitsumi Electric Company Ltd.

Shinichiro Maki

Yoichi Takano

Katsuhiro Yokoyama

Kohei Sakurai

Akihiro Terada

Hiroshi Nozaki

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 supply semiconductor IC includes: an output transistor connected between a voltage-input terminal and a voltage-output terminal; a control circuit that controls the output transistor based on a feedback voltage of an output voltage; a current-limit circuit that limits an output current of the output transistor such that the output current is not equal to or greater than a current limit; a first transistor constituting a current-mirror circuit with the output transistor; a short-circuit-fault detection circuit that detects a short circuit of the voltage-output terminal based on a voltage across a resistor connected in series to the first transistor; and a first output terminal that outputs a detection result of the short-circuit-fault detection circuit. The current limit is within a detection range of the short-circuit-fault detection circuit. The short-circuit-fault detection circuit detects a short circuit of the voltage-output terminal even while the current limit circuit limits the output current.

Power supply semiconductor integrated circuit including a short-circuit-fault detection circuit that detects a short circuit of the voltage-output terminal

A power supply semiconductor integrated circuit includes an output transistor, a control circuit, a first-fault detection circuit, a second-fault detection circuit, a delay circuit, and a latch circuit. The output transistor is connected between a voltage-input terminal to which a DC voltage is input and a voltage-output terminal. The control circuit controls the output transistor. The first-fault detection circuit detects a first fault. The second-fault detection circuit detects a second fault different from the first fault. The delay circuit delays an output of the first-fault detection circuit and an output of the second-fault detection circuit. The latch circuit captures and holds an output of the delay circuit. The delay circuit includes: a constant current source for charging a delay capacitor; a discharge switch for discharging the delay capacitor; and a voltage comparator circuit that compares a charge voltage across the delay capacitor and a predetermined voltage.

Power supply semiconductor integrated circuit

Disclosed is a semiconductor integrated circuit for a regulator, including: a voltage control transistor connected between a voltage input terminal to which a DC voltage is input and an output terminal; a control circuit that controls the voltage control transistor according to a feedback voltage of an output; a first transistor which is provided in parallel with the voltage control transistor and to which an electric current in a proportional reduction from an electric current flowing to the voltage control transistor flows; a first comparison circuit that determines which of the electric current flowing to the first transistor and a predetermined current value is larger; and a first output terminal for outputting the determination result. An output of the first comparison circuit is inverted in response to the flowing to the first transistor of the electric current smaller than a preset rotation lock detection current value.

Semiconductor integrated circuit for regulator, and fan motor system

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 for a regulator includes the following: a voltage controlling transistor; a controlling circuit; a first and second transistor; a first external terminal to connect a current voltage converting element; a first and second voltage comparing circuit which compares a converted voltage with a predetermined comparison voltage and determines which is large or small; and a first and second output terminal which externally outputs a result of comparison by the first and second voltage comparing circuit, respectively. When a current larger than a predetermined open-circuit abnormality detecting current value flows in the first transistor, output of the first voltage comparing circuit is inverted. When a current larger than a predetermined short-circuit abnormality detecting current value flows in the second transistor, output of the second voltage comparing circuit is inverted.

Semiconductor integrated circuit for regulator, which detects abnormalities in a connected load

An output device includes an output transistor that outputs an output current, a first driver that drives the output transistor so that a feedback voltage of an output voltage of the output transistor is in agreement with a reference voltage, an RC circuit that has a capacitor connected to the ground and a resistor connected in series to the capacitor, and a second driver that drives the output transistor to increase the output current when a potential difference between ends of the resistor, generated by the feedback voltage supplied between ends of the RC circuit, is increased by a decrease of the output voltage.

Output device which supplies a current with improved transient response characteristic and reduced current consumption

Disclosed is a low voltage detection circuit. The low voltage detection circuit includes, a voltage comparison circuit, an output stage, an electric current circuit, and a judgment circuit. When the voltage comparison circuit detects that the voltage of the detection target is a predetermined voltage value or less, an output state of the output stage is promptly changed. When the voltage comparison circuit detects that the voltage of the detection target is a predetermined voltage value or more, the output state of the output stage is changed after a delay time obtained by the electric current circuit.

Low voltage detection circuit

A current limiting circuit for limiting an output current in response to a control current includes a detection circuit to detect a detection voltage responsive to an output voltage, and a control current generating circuit to generate a control current responsive to the detection voltage, wherein the control current generating circuit includes a first transistor through which the control current flows, a second transistor that becomes conductive upon a voltage responsive to an amount of the control current being greater than a predetermined voltage above the detection voltage, and a resistor connecting between a base and an emitter of the second transistor to raise a potential at the base of the second transistor above a predetermined level, wherein the amount of the control current flowing through the first transistor decreases as an amount of a current flowing through the second transistor increases.

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Hiratsuka, Japan

Shinichiro Maki