Abstract: This switching power supply 1 has: a switch output stage (101, D1, L1, C2) which generates an output voltage Vout by rectifying and smoothing a switch voltage Vsw that is pulse-driven in response to ON/OFF of an output transistor 101; and a discharge circuit 120 which discharges an output voltage Vout when a state in which the output voltage Vout exceeds a target value continues for a period longer than a prescribed time period. For example, the discharge circuit 120 includes a discharge transistor M1 that is connected to and between a voltage application end of the switch voltage Vsw and a grounding end. The discharge transistor M1 is turned ON/OFF periodically or is kept ON continually for discharge of the output voltage Vout.

Abstract: The present disclosure provides a power integrated circuit (IC) for a switching power supply device that generates an output voltage based on an input voltage. The circuit includes: a high-side transistor, disposed between an input terminal applied with the input voltage and a switch terminal; and a low-side transistor, disposed between the switch terminal and a ground terminal. A feedback control for turning on or off the transistor is performed based on a feedback voltage corresponding to the output voltage. A protection circuit is capable of performing a protection operation for turning on the high-side transistor or the low-side transistor regardless of the feedback control based on a switch voltage at the switch terminal and the input voltage, based on a backflow current from the ground terminal to the switch terminal, or based on the input voltage and a predetermined determination voltage.

Abstract: The present disclosure provides a power supply control device. The power supply control device includes an error amplifier, generating an error voltage according to a difference between a feedback voltage and a reference voltage; a slope voltage generation circuit, generating a slope voltage of a lamp waveform according to an inductor current; a reference voltage generation circuit, generating the reference voltage that depends on an output voltage; a first comparator, generating a reset signal by comparing the error voltage and the slope voltage; a second comparator, generating a skip signal by comparing the error voltage and the reference voltage; an oscillator, generating a set signal; and a controller, receiving an input of each of the signals (set, reset and skip) and performing a switching drive of an output stage in either a fixed on-time control operation or a fixed frequency current mode operation.

Abstract: The present disclosure provides a power integrated circuit (IC) for a switching power supply device that generates an output voltage based on an input voltage. The circuit includes: a high-side transistor, disposed between an input terminal applied with the input voltage and a switch terminal; and a low-side transistor, disposed between the switch terminal and a ground terminal. A feedback control for turning on or off the transistor is performed based on a feedback voltage corresponding to the output voltage. A protection circuit is capable of performing a protection operation for turning on the high-side transistor or the low-side transistor regardless of the feedback control based on a switch voltage at the switch terminal and the input voltage, based on a backflow current from the ground terminal to the switch terminal, or based on the input voltage and a predetermined determination voltage.

Abstract: This switching power supply 1 has: a switch output stage (101, D1, L1, C2) which generates an output voltage Vout by rectifying and smoothing a switch voltage VSW that is pulse-driven in response to ON/OFF of an output transistor 101; and a discharge circuit 120 which discharges an output voltage Vout when a state in which the output voltage Vout exceeds a target value continues for a period longer than a prescribed time period. For example, the discharge circuit 120 includes a discharge transistor M1 that is connected to and between a voltage application end of the switch voltage VSW and a grounding end. The discharge transistor M1 is turned ON/OFF periodically or is kept ON continually for discharge of the output voltage Vout.

Abstract: A DC/DC converter includes a switching element connected to an input voltage so as to be turned on/off, a driving circuit arranged to perform ON/OFF control of the switching element, an inductor arranged to flow current controlled by the switching element, a smoothing capacitor connected to the inductor so as to perform rectifying operation together with the inductor, an oscillator arranged to generate a rectangular wave signal for operating the driving circuit, and an output current detector arranged to detect output detection current flowing in the switching element or the inductor. The oscillator generates the rectangular wave signal at a fixed oscillation frequency when the output detection current is a predetermined value or larger, while it generates the rectangular wave signal at an oscillation frequency lower than the fixed oscillation frequency and proportional to the output detection current when the output detection current is smaller than the predetermined value.

Abstract: A DC/DC converter has: a soft-start circuit, a variable output current generator, a constant current source, an oscillator, a slope circuit, a PWM comparator, and a control circuit operable to turn ON and OFF first and second transistors alternately based on a pulse width modulation signal. Through the switching operation of the first and second transistors, an input voltage is converted into a output voltage.

Abstract: A DC/DC converter includes a switching element connected to an input voltage so as to be turned on/off, a driving circuit arranged to perform ON/OFF control of the switching element, an inductor arranged to flow current controlled by the switching element, a smoothing capacitor connected to the inductor so as to perform rectifying operation together with the inductor, an oscillator arranged to generate a rectangular wave signal for operating the driving circuit, and an output current detector arranged to detect output detection current flowing in the switching element or the inductor. The oscillator generates the rectangular wave signal at a fixed oscillation frequency when the output detection current is a predetermined value or larger, while it generates the rectangular wave signal at an oscillation frequency lower than the fixed oscillation frequency and proportional to the output detection current when the output detection current is smaller than the predetermined value.

Abstract: A DC/DC converter has: a soft-start circuit generating a soft-start input voltage increasing gradually; an error amplifier generating an error signal by comparing an output voltage or a feedback voltage with a reference voltage or the soft-start input voltage, whichever is lower; a variable current generator generating a variable current proportional to the soft-start input voltage or a soft-start output voltage; a constant current source generating a bias current; an oscillator generating a rectangular-wave signal whose frequency varies linearly with a soft-start current which is the sum of the variable current and the bias current; a slope circuit generating a slope signal based on the rectangular-wave signal; a PWM comparator generating a PWM signal based on the error signal and the slope signal; and a control circuit switching transistors alternately based on the PWM signal. Through switching operation of the transistors, an input voltage is converted into the output voltage.