Abstract: A switching converter circuit utilized for converting voltages applied to a first input terminal and a second input terminal into constant voltages to output the constant voltages to a load includes a first switching unit connected between the first and the second input terminals, a second switching unit cascade connected with a third switching unit between the second input terminal and an output terminal, a fourth switching unit connected in parallel with the second and the third switching units, a first comparator to control switching on or off of the third switching unit, a second comparator to control switching on or off of the fourth switching unit, and a controller to control a time to allow the first comparator to output an output signal such that the fourth switching unit is switched off before the third switch is switched off based on the signal output from the first comparator.

Abstract: A switching converter circuit utilized for converting voltages applied to a first input terminal and a second input terminal into constant voltages to output the constant voltages to a load includes a first switching unit connected between the first and the second input terminals, a second switching unit cascade connected with a third switching unit between the second input terminal and an output terminal, a fourth switching unit connected in parallel with the second and the third switching units, a first comparator to control switching on or off of the third switching unit, a second comparator to control switching on or off of the fourth switching unit, and a controller to control a time to allow the first comparator to output an output signal such that the fourth switching unit is switched off before the third switch is switched off based on the signal output from the first comparator.

Abstract: A sound and music playback device includes: an output amplifier; a power supply circuit that supplies electric power to the output amplifier; and an output signal level judging circuit; wherein an output voltage value of the power supply circuit is changed based on a level of a sound and music signal to be outputted.

Abstract: An overcurrent protection circuit includes a current limiter and a status detector, and a voltage regulator includes an output transistor. The output transistor is configured to regulate a voltage input to an input terminal to output a given constant voltage from an output terminal, while passing a current from the input terminal to the output terminal according to a control signal applied thereto. The current limiter reduces the current passed through the output transistor when the passed current exceeds a given current limit. The status detector is configured to generate a status signal indicating operation of the current limiter. A constant voltage regulator incorporating the overcurrent protection circuit is also disclosed.

Abstract: A reversal charge pump circuit generates a negative voltage from an input voltage received from an input terminal, and provides an output terminal with the negative voltage. The charge pump circuit achieves increased voltage stability and avoids breakdown voltage problems, with an uncomplicated structure. The circuit may have first and second capacitors, first through fourth switches, and a voltage control circuit. The voltage control circuit controls the voltage provided to the first capacitor. The switches are on/off controlled by signals from a control circuit.

Abstract: A constant-voltage power supply circuit is disclosed that is able to prevent overshoot of an output voltage possibly occurring when changing a constant-voltage circuit in operation and is able to supply a constant output voltage. The constant-voltage power supply circuit includes a first constant-voltage circuit, having a first output transistor and a first output voltage controller, that generates a first reference voltage and generates a first proportional voltage in proportion to a voltage on an output terminal, and a second constant-voltage circuit having a second output transistor and a second output voltage controller that generates a second reference voltage and generates a second proportional voltage in proportion to the voltage on the output terminal.

Abstract: An overcurrent protection circuit includes a current limiter and a status detector, and a voltage regulator includes an output transistor. The output transistor is configured to regulate a voltage input to an input terminal to output a given constant voltage from an output terminal, while passing a current from the input terminal to the output terminal according to a control signal applied thereto. The current limiter reduces the current passed through the output transistor when the passed current exceeds a given current limit. The status detector is configured to generate a status signal indicating operation of the current limiter. A constant voltage regulator incorporating the overcurrent protection circuit is also disclosed.

Abstract: A constant-voltage power circuit incorporating an over-current protection circuit having a fold back current limiting capability operative through low input voltages, and being capable of arbitrarily setting current outputs. The constant-voltage power supply circuit is configured so that a voltage output with small amplitude from a differential amplifier circuit is subjected to amplitude expansion to be amplified to range fully from the ground potential approximately to the input voltage by means of an amplitude expansion circuit, which includes an inverter consisting of an NMOS transistor and a resistor, and that the voltage resulting from the amplitude expansion is subsequently input to the gate of a PMOS transistor configured to directly control an output transistor.

Abstract: A reversal charge pump circuit generates a negative voltage from an input voltage received from an input terminal, and provides an output terminal with the negative voltage. The charge pump circuit achieves increased voltage stability and avoids breakdown voltage problems, with an uncomplicated structure. The circuit may have first and second capacitors, first through fourth switches, and a voltage control circuit. The voltage control circuit controls the voltage provided to the first capacitor. The switches are on/off controlled by signals from a control circuit.

Abstract: A constant-voltage power supply circuit is disclosed that is able to prevent overshoot of an output voltage possibly occurring when changing a constant-voltage circuit in operation and is able to supply a constant output voltage. The constant-voltage power supply circuit includes a first constant-voltage circuit, having a first output transistor and a first output voltage controller, that generates a first reference voltage and generates a first proportional voltage in proportion to a voltage on an output terminal, and a second constant-voltage circuit having a second output transistor and a second output voltage controller that generates a second reference voltage and generates a second proportional voltage in proportion to the voltage on the output terminal.

Abstract: A constant-voltage power supply circuit is disclosed that is able to prevent overshoot of an output voltage possibly occurring when changing a constant-voltage circuit in operation and is able to supply a constant output voltage. The constant-voltage power supply circuit includes a first constant-voltage circuit, having a first output transistor and a first output voltage controller, that generates a first reference voltage and generates a first proportional voltage in proportion to a voltage on an output terminal, and a second constant-voltage circuit having a second output transistor and a second output voltage controller that generates a second reference voltage and generates a second proportional voltage in proportion to the voltage on the output terminal.

Abstract: A constant-voltage power circuit incorporating an over-current protection circuit having a fold back current limiting capability operative through low input voltages, and being capable of arbitrarily setting current outputs. The constant-voltage power supply circuit is configured so that a voltage output with small amplitude from a differential amplifier circuit is subjected to amplitude expansion to be amplified to range fully from the ground potential approximately to the input voltage by means of an amplitude expansion circuit, which includes an inverter consisting of an NMOS transistor and a resistor, and that the voltage resulting from the amplitude expansion is subsequently input to the gate of a PMOS transistor configured to directly control an output transistor.

Abstract: A constant-voltage power circuit incorporating an over-current protection circuit having a fold back current limiting capability operative through low input voltages, and being capable of arbitrarily setting current outputs. The constant-voltage power supply circuit is configured so that a voltage output with small amplitude from a differential amplifier circuit is subjected to amplitude expansion to be amplified to range fully from the ground potential approximately to the input voltage by means of an amplitude expansion circuit, which includes an inverter consisting of an NMOS transistor and a resistor, and that the voltage resulting from the amplitude expansion is subsequently input to the gate of a PMOS transistor configured to directly control an output transistor.

Abstract: A constant-voltage power supply circuit is disclosed that is able to prevent overshoot of an output voltage possibly occurring when changing a constant-voltage circuit in operation and is able to supply a constant output voltage. The constant-voltage power supply circuit includes a first constant-voltage circuit, having a first output transistor and a first output voltage controller, that generates a first reference voltage and generates a first proportional voltage in proportion to a voltage on an output terminal, and a second constant-voltage circuit having a second output transistor and a second output voltage controller that generates a second reference voltage and generates a second proportional voltage in proportion to the voltage on the output terminal.

Abstract: A constant-voltage power circuit incorporating an over-current protection circuit having a fold back current limiting capability operative through low input voltages, and being capable of arbitrarily setting current outputs. The constant-voltage power supply circuit is configured so that a voltage output with small amplitude from a differential amplifier circuit is subjected to amplitude expansion to be amplified to range fully from the ground potential approximately to the input voltage by means of an amplitude expansion circuit, which includes an inverter consisting of an NMOS transistor and a resistor, and that the voltage resulting from the amplitude expansion is subsequently input to the gate of a PMOS transistor configured to directly control an output transistor.