Abstract: A minimum pulse signal generating circuit generates a minimum pulse signal having a predetermined minimum duty ratio, synchronously with a PWM signal. When the duty ratio of the PWM signal is smaller than the minimum duty ratio, a corrected pulse signal generating circuit fixes the logical level of the PWM signal to the level that turns off a switching transistor. A driver circuit drives the switching transistor according to a corrected PWM signal output from the corrected pulse signal generating circuit. In a case in which the level of the PWM signal is fixed by means of the corrected pulse signal generating circuit, a stop signal generating circuit generates a stop signal at a predetermined first level. When the stop signal is at the predetermined first level, at least an oscillator used for pulse modulation is stopped.

Abstract: A pulse frequency modulator generates a pulse signal having a fixed duty ratio and a frequency which is adjusted such that a feedback voltage corresponding to the output voltage of a charge pump circuit is coincident with a predetermined first reference voltage. A driver, on receiving the pulse signal, turns on a first or second group of switches during the time periods corresponding to the high time periods of the pulse signal and turns on the other ones of the first and second group of switches during the time periods corresponding to the low time periods of the pulse signal.

Abstract: A charge pump circuit includes a first switch to a fourth switch, a flying capacitor, and an output capacitor. A driver turns on the first switch and the fourth switch during a predetermined precharge period from the start of activation of the charge pump circuit to charge the output capacitor. Thereafter, on the basis of a pulse signal, the driver alternately turns on and off a first pair and a second pair.

Abstract: A pulse frequency modulator generates a pulse signal having a fixed duty ratio and a frequency which is adjusted such that a feedback voltage corresponding to the output voltage of a charge pump circuit is coincident with a predetermined first reference voltage. A driver, on receiving the pulse signal, turns on a first or second group of switches during the time periods corresponding to the high time periods of the pulse signal and turns on the other ones of the first and second group of switches during the time periods corresponding to the low time periods of the pulse signal.

Abstract: A switching power supply apparatus generates a first output voltage with a reversed polarity of an input voltage and a second input voltage of double the input voltage with the reversed polarity, and then outputs them from the first output terminal and the second output terminal. A driver circuit includes a control unit and a first switch to a sixth switch. The driver circuit repeats three charging periods in a time-division manner. The three charging periods are a first charging period during which a flying capacitor is charged with the input voltage, a second charging period in which a low-potential-side terminal of the flying capacitor is connected to a ground terminal and a first output capacitor is charged with a voltage appearing at the other end of the flying capacitor, and a third charging period in which a high-potential-side of the flying capacitor is connected with the first output terminal and a second output capacitor is charged with a voltage appearing at the other end of the flying capacitor.

Abstract: A first switch group includes switches provided on a path for charging a flying capacitor using an input voltage. A second switch group includes switches provided on a path for charging an output capacitor using charge stored in the flying capacitor. A pulse modulator generates a pulse signal having a duty ratio adjusted so that a feedback voltage corresponding to an output voltage of a charge pump circuit matches a given reference voltage. A driver receives the pulse signal from the pulse modulator, and turns on either one of the first switch group and the second switch group during a period corresponding to a high-time of the pulse signal and turns on the other switch group during a period corresponding to a low-time thereof.

Abstract: A first constant-current source supplies a charging current to a second terminal of a first capacitor in which a first terminal is grounded. A first terminal of a second capacitor is grounded, and a first switch is provided between the second terminal of the first capacitor and a second terminal of the second capacitor. A second constant-current source supplies current to the second capacitor, and a second switch is provided on a current path of the second constant-current source. A third constant-current source draws out current from the first capacitor and the second capacitor. A switch controller turns on the first switch and turns off the second switch when an output voltage appearing in the second terminal of the first capacitor reaches a predetermined upper-limit voltage. The switch controller turns off the first switch and turns on the second switch when the output voltage drops to a predetermined lower-limit voltage.

Abstract: A first charge pump circuit converts an input voltage (Vin) into a predetermined voltage, to be outputted as a first output voltage (Vout1). A second charge pump circuit converts the first output voltage (Vout1), outputted from the first charge pump circuit, into a predetermined voltage, to be outputted as a second output voltage (Vout2). A control circuit controls charge-discharge states of the first charge pump circuit and the second charge pump circuit. The control circuit synchronously controls a state in which a first output capacitor of the first charge pump circuit is charged, and a state in which a second flying capacitor of the second charge pump circuit is charged.

Abstract: A minimum pulse signal generating circuit generates a minimum pulse signal having a predetermined minimum duty ratio, synchronously with a PWM signal. When the duty ratio of the PWM signal is smaller than the minimum duty ratio, a corrected pulse signal generating circuit fixes the logical level of the PWM signal to the level that turns off a switching transistor. A driver circuit drives the switching transistor according to a corrected PWM signal output from the corrected pulse signal generating circuit. In a case in which the level of the PWM signal is fixed by means of the corrected pulse signal generating circuit, a stop signal generating circuit generates a stop signal at a predetermined first level. When the stop signal is at the predetermined first level, at least an oscillator used for pulse modulation is stopped.

Abstract: A control signal Vcont is input to a control terminal, thereby switching between a normal operation mode and a light-load mode. In the normal mode, a control unit turns on/off first switch through fourth switch, and outputs boosted voltages from a first output terminal and a second output terminal. When the light-load mode is selected, the control unit stops the switching of the second switch and fourth switch. In this case, current flows in first and second output capacitors via first and second diodes, respectively, and boosting operation is performed.

Abstract: In a switching power supply apparatus, an input voltage Vin applied to an input terminal is output from a first output terminal and a second output terminal after boosting or inverting of the voltage Vin. When a first and a fourth switches are turned on, a flying capacitor is charged. When a second and a fifth switches are turned on, charges charged in the flying capacitor are transferred to a first output capacitor. When a third and a fifth switches are turned on, charges charged in the flying capacitor are transferred to a second output capacitor. A voltage Vin×2 double the input voltage Vin is output from the first output terminal as a first output voltage Vout1, and a voltage ?Vin obtained by inverting the input voltage is output from the second output terminal as a second output voltage.

Abstract: A switching power supply apparatus generates a first output voltage with a reversed polarity of an input voltage and a second input voltage of double the input voltage with the reversed polarity, and then outputs them from the first output terminal and the second output terminal. A driver circuit includes a control unit and a first switch to a sixth switch. The driver circuit repeats three charging periods in a time-division manner. The three charging periods are a first charging period during which a flying capacitor is charged with the input voltage, a second charging period in which a low-potential-side terminal of the flying capacitor is connected to a ground terminal and a first output capacitor is charged with a voltage appearing at the other end of the flying capacitor, and a third charging period in which a high-potential-side of the flying capacitor is connected with the first output terminal and a second output capacitor is charged with a voltage appearing at the other end of the flying capacitor.

Abstract: A first charge pump circuit converts an input voltage (Vin) into a predetermined voltage, to be outputted as a first output voltage (Vout1). A second charge pump circuit converts the first output voltage (Vout1), outputted from the first charge pump circuit, into a predetermined voltage, to be outputted as a second output voltage (Vout2). A control circuit controls charge-discharge states of the first charge pump circuit and the second charge pump circuit. The control circuit synchronously controls a state in which a first output capacitor of the first charge pump circuit is charged, and a state in which a second flying capacitor of the second charge pump circuit is charged.

Abstract: A first constant-current source supplies a charging current to a second terminal of a first capacitor in which a first terminal is grounded. A first terminal of a second capacitor is grounded, and a first switch is provided between the second terminal of the first capacitor and a second terminal of the second capacitor. A second constant-current source supplies current to the second capacitor, and a second switch is provided on a current path of the second constant-current source. A third constant-current source draws out current from the first capacitor and the second capacitor. A switch controller turns on the first switch and turns off the second switch when an output voltage appearing in the second terminal of the first capacitor reaches a predetermined upper-limit voltage. The switch controller turns off the first switch and turns on the second switch when the output voltage drops to a predetermined lower-limit voltage.

Abstract: A seating level adjusting device includes an elevating mechanism attached on a frame of the vehicle seat for raising or lowering the seating level, and a handle assembly separatably connected with the elevating mechanism for manipulating the elevating mechanism. The handle assembly carries an actuating mechanism for actuating the elevating mechanism, a locking mechanism for locking the actuating mechanism, and a releasing mechanism for releasing the lock state of the actuating mechanism. When repairing one of the actuating, locking, and releasing mechanisms, the handle assembly is separated from the elevating mechanism. The repair can be easily accomplished.