Abstract: A DC/DC converter includes a main switching element and a subordinate switching element, and is arranged to supply power to load via a coil. The ON-time of a subordinate switching element in a succeeding cycle is controlled based on a period of time tdif from the time when the subordinate switching element is turned off until the time when voltage at the point of connection of the two switching elements reaches a predetermined threshold value.

Abstract: A switching power supply circuit comprises: current detection means for detecting a current flowing through an inductor; current holding means for holding the current flowing through the inductor over a past predetermined period; and current superposition means for adding to an output of an error amplifier a current superposition signal which makes an adjustment, based on a present current information signal as an output signal of the current detection means, such that the ON-period of a switching signal of a PWM comparator is shortened, and also makes an adjustment, based on a past current information signal as an output signal of the current holding means, such that the ON-period of the switching signal of the PWM comparator is lengthened.

Abstract: In a phase compensation circuit having a resistance connected to the output side of an error amplifier, a capacitor, and a conductance amplifier functioning as a capacitance amplifier circuit, capacitance is amplified by the conductance amplifier and used, whereby an essentially required capacitance is ensured, even when the capacitance of the capacitor is small.

Abstract: A DC/DC converter includes a main switching element and a subordinate switching element, and is arranged to supply power to load via a coil. The ON-time of a subordinate switching element in a succeeding cycle is controlled based on a period of time tdif from the time when the subordinate switching element is turned off until the time when voltage at the point of connection of the two switching elements reaches a predetermined threshold value.

Abstract: In a power circuit which makes phase compensation by utilizing ESR of an output capacitor, a feedback signal based on an output voltage is supplied by a coupling capacitor to an N-channel MOS transistor on a saturated coupling side of a current mirror circuit inside an error amplification circuit.

Abstract: A switching power supply circuit comprises: current detection means for detecting a current flowing through an inductor; current holding means for holding the current flowing through the inductor over a past predetermined period; and current superposition means for adding to an output of an error amplifier a current superposition signal which makes an adjustment, based on a present current information signal as an output signal of the current detection means, such that the ON-period of a switching signal of a PWM comparator is shortened, and also makes an adjustment, based on a past current information signal as an output signal of the current holding means, such that the ON-period of the switching signal of the PWM comparator is lengthened.

Abstract: A switching power supply circuit has a current mode control circuit including current detection means, and current mode signal generation means for generating a current mode signal being a drain current of a first MOS transistor obtained by supplying a first current information signal, which is an output signal of the current detection means, to the gate of the first MOS transistor, and by connecting a first resistance to the source of the first MOS transistor, and supplies the current mode signal to a feedback control system of the switching power supply circuit.

Abstract: A stabilized power supply circuit includes a charge pump power supply circuit including four switching elements and a capacitor, and an error amplifier comparing the output voltage of the charge pump power supply circuit and a reference voltage and outputting an error signal on the basis of the difference therebetween. A current source is connected in series to the gate of a switching element formed of a MOSFET. The period during which electric charge is discharged from the gate is controlled in accordance with the error signal in order to maintain the output voltage constant.

Abstract: A control circuit for a DC/DC converter which includes a main switching element, a sub switching element, and a reactor in order to convert a DC input voltage to a DC output voltage. The control circuit comprises a clock signal generator for generating a clock signal during a blank period in which both the main and sub switching elements are off; a comparator for comparing a reference voltage and a voltage at a connection point between the main and sub switching elements and for outputting a comparison signal indicating a relation of magnitude between the reference voltage and the voltage at the connection point; and an operation mode switching section for monitoring the comparison signal at a timing corresponding to the clock signal in order to detect a voltage state at the connection point, and controlling the sub switching element in accordance with the voltage state.

Abstract: To provide a switching regulator with a small packaging area.

Abstract: A control circuit for a DC/DC converter which includes a main switching element, a sub switching element, and a reactor in order to convert a DC input voltage to a DC output voltage. The control circuit comprises a clock signal generator for generating a clock signal during a blank period in which both the main and sub switching elements are off; a comparator for comparing a reference voltage and a voltage at a connection point between the main and sub switching elements and for outputting a comparison signal indicating a relation of magnitude between the reference voltage and the voltage at the connection point; and an operation mode switching section for monitoring the comparison signal at a timing corresponding to the clock signal in order to detect a voltage state at the connection point, and controlling the sub switching element in accordance with the voltage state.