Abstract: The present disclosure relates to a high-side transistor drive circuit, a switching circuit and a controller of a DC/DC converter. A pulse generator generates a first pulse that becomes high level for a certain period of time in response to a first edge of an input signal and a second pulse that becomes high level for a certain period of time in response to a second edge of the input signal. An open drain circuit has a first output node that becomes low level in response to the first pulse and a second output node that becomes low level in response to the second pulse. A first current mirror circuit folds back a first current flowing through the first output node of the open drain circuit. A second current mirror circuit folds back a second current flowing through the second output node of the open drain circuit.

Abstract: Disclosed is a control circuit of a boost DC-DC converter including a high side transistor and a low side transistor, and a load switch connected between the high side transistor and an output line of the boost DC-DC converter. The control circuit includes a pulse modulator that generates a pulse signal with a pulse modulated to bring an output voltage of the output line close to a target level, a logic circuit that generates a high side control signal and a low side control signal based on the pulse signal, a load switch drive circuit that drives a first PMOS transistor provided as the load switch, and a current detection circuit that generates a current detection signal indicating a current flowing through the first PMOS transistor. The load switch drive circuit is switchable between a first mode and a second mode.

Abstract: A control circuit of a boost DC/DC converter including a high side transistor and a low side transistor, includes a pulse modulator including a first error amplifier that amplifies an error between a reference voltage and a feedback signal corresponding to an output voltage of the converter, the pulse modulator being configured to generate a pulse signal with a pulse modulated, a logic circuit that generates a high side control signal and a low side control signal, and a load switch drive circuit that drives a load switch that is a PMOS transistor connected between the high side transistor and a load. The load switch drive circuit can make a switch between a first mode for fully turning on the PMOS transistor and a second mode for supplying a drive voltage corresponding to the output signal of the first error amplifier to a gate of the PMOS transistor.

Abstract: The present disclosure relates to a buck DC/DC converter, a controller thereof and controlling method thereof, and an electronic device. A pulse modulator generates a pulse modulation signal such that an output of the buck DC/DC converter is pulse-modulated to approach a target state. An overcurrent detection circuit compares a low-side current flowing through a low-side transistor with a predetermined overcurrent threshold value to generate an overcurrent detection signal that is asserted when the low-side current is greater than the overcurrent threshold value. (i) In a first mode, the control pulse that is input to the driver circuit corresponds to the pulse modulation signal, and (ii) in a second mode, the control pulse takes a second level for a period during which the overcurrent detection signal is asserted and takes a first level during a fixed on time after the overcurrent detection signal is negated.

Abstract: The present disclosure provides a current detecting circuit, a synchronous rectification type DC/DC buck converter and a control circuit thereof. The current detection circuit is used with a push-pull switching circuit to detect a source current flowing in a low-side transistor. The switching circuit, (i) in a first phase, connects a first end of the capacitor to a ground line, and connects a second end of the capacitor to a switch line connecting a high-side transistor and the low-side transistor. The switching circuit, (ii) in a second phase, sets the first end of the capacitor to a high impedance, and connects a second end of the capacitor to the ground line. An output circuit has a high impedance input and outputs a current detection signal based on a voltage generated at the first end of the capacitor in the second phase.

Abstract: The present disclosure relates to a high-side transistor drive circuit, a switching circuit and a controller of a DC/DC converter. A pulse generator generates a first pulse that becomes high level for a certain period of time in response to a first edge of an input signal and a second pulse that becomes high level for a certain period of time in response to a second edge of the input signal. An open drain circuit has a first output node that becomes low level in response to the first pulse and a second output node that becomes low level in response to the second pulse. A first current mirror circuit folds back a first current flowing through the first output node of the open drain circuit. A second current mirror circuit folds back a second current flowing through the second output node of the open drain circuit.

Abstract: A slew rate control device for controlling a slew rate, includes: a setting part configured to set a voltage value used to determine the slew rate; and a control part configured to control the slew rate, based on the voltage value set by the setting part, so that the slew rate becomes slower as an output voltage of a power supply approaches from a transition starting voltage to a target voltage.

Abstract: A pulse modulator generates a pulse signal, such that an output signal of a DC/DC converter approaches a target value. When a detection value of a coil current of the DC/DC converter crosses a threshold for zero crossing, a reverse flow detection circuit asserts a reverse flow detection signal and turns off a synchronous rectification transistor of the DC/DC converter. An optimizer controls an operation parameter of the reverse flow detection circuit, on the basis of a cycle of the pulse signal.

Abstract: A slew rate control device for controlling a slew rate, includes: a setting part configured to set a voltage value used to determine the slew rate, and a control part configured to control the slew rate, based on the voltage value set by the setting part, so that the slew rate becomes slower as an output voltage of a power supply approaches from a transition starting voltage to a target voltage.

Abstract: A DC/DC converter comprises: inductors L provided for respective channels; switching circuits provided for the respective channels; and a controller configured to change the number of channels to be activated, i.e., K, according to an amount of a load current IOUT that flows through a load, and to control the switching circuits that correspond to the activated channels such that a feedback voltage VFB that corresponds to an output voltage VOUT matches a predetermined target voltage VREF. The controller activates only a single channel in a lightest load state. The inductance L of the inductor L provided for the aforementioned single channel is set to a value that differs from the inductances of the inductors L of the other channels so as to provide high efficiency in the lightest load state.

Abstract: The present invention improves the efficiency of a switching power supply in a light load. A control circuit is configured to repeat a driving duration enabling the switching element to be switched and a stop duration stopping the switching in a light load state. A pulse signal generating portion generates a driving pulse signal, in which the driving pulse signal at least includes a pulse in the driving duration, and the lighter a load is, the less the number of pulses in the driving duration is. A first driver drives a first switching transistor according to the at least one pulse in the driving pulse signal other than predetermined K pulses (K is a natural number). The K pulses are in the driving pulse signal when the number of the pulses is reduced to K.

Abstract: A charging circuit receives electric power from a solar battery, and charges a secondary battery. A charging current detection unit generates a detection signal that corresponds to a charging current supplied from a DC/DC converter to the secondary battery. A control circuit generates a reference voltage that corresponds to the detection signal. A driving unit generates a pulse signal having a duty ratio that is adjusted such that the voltage output from the solar battery matches the reference voltage, and performs switching of a switching transistor according to the pulse signal. A control circuit adjusts the reference voltage such that the reference voltage becomes greater.

Abstract: An error amplifier generates an error signal VERR that corresponds to the difference between a feedback signal VFB and a predetermined reference voltage VREF. A first oscillator generates a first cyclic signal VOSC1 having a sloping segment and a first frequency. A second oscillator generates a second cyclic signal VOSC2 having a sloping segment and a second frequency that is lower than the first frequency. A first pulse modulator generates a first pulse signal having a pulse width that corresponds to the error signal VERR, and clamps its pulse width such that it does not become smaller than a first minimum pulse width. A second pulse modulator generates a second pulse signal having a pulse width that corresponds to the error signal VERR. A synthesizing unit combines the first pulse signal and the second pulse signal so as to generate a driving pulse signal.

Abstract: The present invention improves the efficiency of a switching power supply in a light load. A control circuit is configured to repeat a driving duration enabling the switching element to be switched and a stop duration stopping the switching in a light load state. A pulse signal generating portion generates a driving pulse signal, in which the driving pulse signal at least includes a pulse in the driving duration, and the lighter a load is, the less the number of pulses in the driving duration is. A first driver drives a first switching transistor according to the at least one pulse in the driving pulse signal other than predetermined K pulses (K is a natural number). The K pulses are in the driving pulse signal when the number of the pulses is reduced to K.

Abstract: A charging circuit receives electric power from a solar battery, and charges a secondary battery. A charging current detection unit generates a detection signal that corresponds to a charging current supplied from a DC/DC converter to the secondary battery. A control circuit generates a reference voltage that corresponds to the detection signal. A driving unit generates a pulse signal having a duty ratio that is adjusted such that the voltage output from the solar battery matches the reference voltage, and performs switching of a switching transistor according to the pulse signal. A control circuit adjusts the reference voltage such that the reference voltage becomes greater.

Abstract: An error amplifier generates an error signal VERR that corresponds to the difference between a feedback signal VFB and a predetermined reference voltage VREF. A first oscillator generates a first cyclic signal VOSC1 having a sloping segment and a first frequency. A second oscillator generates a second cyclic signal VOSC2 having a sloping segment and a second frequency that is lower than the first frequency. A first pulse modulator generates a first pulse signal having a pulse width that corresponds to the error signal VERR, and clamps its pulse width such that it does not become smaller than a first minimum pulse width. A second pulse modulator generates a second pulse signal having a pulse width that corresponds to the error signal VERR. A synthesizing unit combines the first pulse signal and the second pulse signal so as to generate a driving pulse signal.

Abstract: A pulse signal generating circuit generates a pulse signal having a duty ratio controlled such that the output voltage approaches a reference voltage. A driver circuit generates first and second gate voltages, which are to be respectively applied to the gates of a switching transistor and a synchronous rectifier transistor, based upon the pulse signal. A threshold voltage generating unit generates a threshold voltage which is synchronous with the second gate voltage, and which is in the high-level state during a period when the synchronous rectifier transistor is to be turned off and in the low-level state during a period when the synchronous rectifier transistor is to be turned on. A light-load detection comparator compares a switching voltage with the threshold voltage, and outputs a light-load detection signal.

Abstract: A switching regulator according to the invention includes a resistor (R3) and a capacitor (C3) for generating a ramp signal from the AC component in the output of a hysteresis comparator (1). The switching regulator is characterized in that the hysteresis comparator (1) compares with a reference voltage outputted from a reference voltage source (2) a voltage obtained by superimposing the ramp signal on the divided voltage of the output voltage (VO) as obtained between resistors (R1 and R2).

Abstract: A power supply unit comprises a series regulator and a switching DC-DC converter controlled by a PWM signal and connected in parallel with the series regulator, which are switchably enabled by a mode instruction signal depending on the magnitude of a load current. In switching the series regulator and the DC-DC converter, they are simultaneously enabled for a predetermined overlapping time. Further, in changing the operating condition of the DC-DC converter, the width of the PWM signal is shortened to extend the dead time of the DC-DC converter by a predetermined period, thereby suppressing free oscillations and accompanying overshoots that could take place in the power supply unit during switching.

Abstract: A pulse signal generating circuit generates a pulse signal having a duty ratio controlled such that the output voltage approaches a reference voltage. A driver circuit generates first and second gate voltages, which are to be respectively applied to the gates of a switching transistor and a synchronous rectifier transistor, based upon the pulse signal. A threshold voltage generating unit generates a threshold voltage which is synchronous with the second gate voltage, and which is in the high-level state during a period when the synchronous rectifier transistor is to be turned off and in the low-level state during a period when the synchronous rectifier transistor is to be turned on. A light-load detection comparator compares a switching voltage with the threshold voltage, and outputs a light-load detection signal.