Murata Manufacturing Co., Ltd.

Yoshiyuki Uno

Tatsuya Hosotani

Hajime Shiji

Akio Nishida

Yoshiaki Mizushima

Tomokuni Tokugawa

Hiroshi Takemura

Shouhei Hirose

A DC-DC converter includes a synchronous rectification converter that converts electric power, a voltage detection circuit that detects a voltage proportional to an output voltage of the converter, a converter controller that compares a detection voltage detected by the voltage detection circuit with a reference voltage and controls an operation of the converter to provide a constant or substantially constant voltage of the detection voltage, and a command processor that sets, in a case where a target voltage command value input from an ECU is lower than a voltage value of the output voltage of the converter, a voltage value of the reference voltage to be equal or substantially equal to a voltage value of the detection voltage.

Synchronous rectification DC-DC converter and switching power supply device

An abnormality determiner turns OFF a third switch and controls a converter controller to stop operating in a case where a voltage value detected by a voltage detector during a normal mode exceeds a first threshold value. The abnormality determiner determines that a first switch has an abnormality in a case where the voltage value exceeds a second threshold value in a state where the converter controller is stopped. The abnormality determiner controls the converter controller to operate in a case where the voltage value is equal to or smaller than the second threshold value in a state where the converter controller is stopped. The abnormality determiner determines that the converter controller has an abnormality in a case where the voltage value exceeds a third threshold value in a state where the converter controller is operated.

Power supply apparatus

In a switching power supply apparatus, a magnitude of an output current of a first converter, which has been detected in a state in which a second converter is stopped, is transmitted to a measurement tool and a magnitude of an output current of the second converter, which has been detected in a state in which the first converter is stopped, is transmitted to the measurement tool. Correction values determined by the measurement tool based on transmission contents are received and stored in a memory. A magnitude of the output current which is used for PWM control of the first converter and a magnitude of the output current which is used for PWM control of the second converter are respectively corrected with the correction values.

Switching power supply apparatus and error correction method

In a switching power-supply apparatus that controls magnitudes of output voltages of respective converters connected in parallel to be equal to a target voltage value, only a selected one of the converters is made to operate. In this state, correction values generated by the respective converters are received and stored in memory. Droop characteristics generated for the respective converters are corrected using the correction values. Accordingly, a switching power-supply apparatus and a droop characteristic correction method capable of correcting variations in droop characteristics generated for respective power converters are provided.

Switching power-supply apparatus and droop characteristic correction method

A power supply system includes a plurality of power supply apparatuses whose inputs and outputs are respectively connected in parallel with one another. The output of each of the plurality of power supply apparatuses is wired-OR connected to a synchronization pulse bus line in an open collector structure or an open drain structure. The plurality of power supply apparatuses each include a synchronization pulse generator generating a synchronization pulse for synchronization of a switching cycle, and a switching control circuit, connected to the synchronization pulse bus line, performing switching control of a switch device in synchronization with a signal of the synchronization pulse bus line. There is no distinction between a master power supply apparatus and a slave power supply apparatus in the plurality of power supply apparatuses. Further, generation of noise due to a transmission line for a synchronization signal is avoided.

Power supply system and power supply apparatus

A switching power supply apparatus includes a step-down converter that steps down an input current by turning on/off switching elements, a switching element electrically connected between the step-down converter and voltage outputs, and a microcontroller. An input-side resistor voltage dividing circuit and an output-side resistor voltage dividing circuit including elements with the same or similar specifications are electrically connected to the input and output of the switching element, respectively. The microcontroller stores coefficients of an expression which have been externally calculated according to a voltage detected by the output-side resistor voltage dividing circuit and a voltage detected at the voltage output portions. The microcontroller corrects a measurement value of an intermediate bus voltage detected by the input-side resistor voltage dividing circuit according to an expression and the stored coefficients.

Switching power supply apparatus

A switching power supply apparatus includes a voltage step-up converter that increases input voltage in response to turning on and off of a switching element, a transformer including a primary winding and a secondary winding and the primary winding of which is connected to the output of the voltage step-up converter, a microcontroller that controls the turning on and off of the switching element, an input voltage detection circuit that detects input voltage of the microcontroller, and an intermediate bus voltage detection circuit that detects intermediate bus voltage from the microcontroller. The input voltage detection circuit and the intermediate bus voltage detection circuit are circuits including elements having the same specifications. The microcontroller controls the turning on and off of the switching element based on a result of calculation from voltage values detected by the input voltage detection circuit and the intermediate bus voltage detection circuit.

A resonant converter circuit generates an output voltage from an input voltage by switching first and second FETs. A subsequent-stage switching control circuit alternately subjects the first and second FETs in the resonant converter circuit to on/off control with a fixed on-duty ratio and a fixed switching frequency. A boost converter circuit includes an inductor, a smoothing capacitor, and a third FET arranged to switch the energization of the inductor. A previous-stage switching control circuit subjects the third FET in the boost converter circuit to on/off control with a controlled on-duty ratio, and adjusts an output voltage to the resonant converter circuit.

Switching power-supply device

A resonant capacitor and an inductor are connected in series between a primary winding of a transformer and a second switching element. A first rectifying and smoothing circuit including a first rectifier switching element and a capacitor rectifies and smoothes a voltage generated in a first secondary winding of the transformer, and takes out a first output voltage. A second rectifying and smoothing circuit including a second rectifier switching element and a capacitor rectifies and smoothes a voltage generated in a second secondary winding of the transformer, and takes out a second output voltage. A control circuit controls an on-time of a first switching element and an on-time of the second switching element in accordance with the first output voltage and the second output voltage, respectively.

Switching power supply apparatus including a plurality of outputs

In a switching power supply apparatus, a resonant capacitor and an inductor are connected in series between a primary winding in a transformer and a second switching element. A first rectifier smoothing circuit including a diode and a capacitor rectifies and smoothes a voltage occurring at a first secondary winding in the transformer during an on period of a first switching element to extract a first output voltage. A second rectifier smoothing circuit including a diode and a capacitor rectifies and smoothes a voltage occurring at a second secondary winding in the transformer during an on period of the second switching element to extract a second output voltage. A control circuit controls an on time of the first switching element and an on time of the second switching element on the basis of the first output voltage and the second output voltage.

Switching power supply apparatus including simultanous control of multiple outputs

In a switching power supply apparatus, an alternating-current input power supply is input to the input terminals of a power factor correction converter and a DC-DC converter is connected to output terminals. A load is connected to the output of the DC-DC converter. A digital signal processing circuit takes the product of an output voltage error and a detection value of the input voltage as a current reference amplitude value and controls the on period of a switching element in accordance with the difference between the current reference amplitude value and the current flowing through an inductor. The target value of the output voltage or the output voltage error is corrected using a value that is proportional to the current reference amplitude value such that the output voltage rises as the load goes from a light to a heavy load state.

Switching power supply apparatus including a PFC converter that suppresses harmonic currents

In a switching power supply apparatus, a comparator outputs a first determination criterion signal based on a saw-tooth wave signal whose level fluctuates with a constant period and a detection voltage signal. An inverter subjects the first determination criterion signal to reverse processing, and outputs a second determination criterion signal. The comparator outputs a first switching judgment-use signal from a monitor signal and a threshold value, and the comparator outputs a second switching judgment-use signal from the monitor signal and the threshold value. An AND circuit outputs the first switching control signal from the first determination criterion signal and the first switching judgment-use signal, and the AND circuit outputs the second switching control signal from the second determination criterion signal and the second switching judgment-use signal.

Switching power supply apparatus including a plurality of switching elements

A switching power supply apparatus includes a PFC converter, a DC-DC converter, and primary-side and secondary-side digital control circuits that control the PFC converter and the DC-DC converter. On the basis of a voltage detected by an output voltage detection circuit, the primary-side digital control circuit transmits data about the on-time of a switching element of the DC-DC converter to the primary-side digital control circuit. On the basis of this data, the primary-side digital control circuit controls the on-time of the switching element.

Isolated switching power supply apparatus including primary-side and secondary-side digital control circuits

A PFC converter that prevents and reduces switching losses by controlling ripple of inductor current and enables application for high power usage, includes a switching device that is turned off when an inductor current flowing through an inductor reaches a first threshold value, and turned on when the inductor current reaches a second threshold value. A switching control circuit sets a reference value of the inductor current using results from an input voltage detection circuit and an output voltage detection circuit. The first threshold value is produced by adding a predetermined value to the reference value, and the second threshold value is produced by subtracting the predetermined value from the reference value.

PFC converter using a predetermined value that varies in synchronization with a phase of the input voltage

A power factor correction converter includes a diode bridge that rectifies an alternating-current voltage input from an alternating-current input power supply Vac, a series circuit including an inductor and a switching element, a rectifying smoothing circuit connected in parallel with the switching element and including a diode and a smoothing capacitor, and a digital signal processing circuit that controls turning on and off of the switching element such that the input current input from the alternating-current input power supply Vac comes to have a similar shape to the alternating-current voltage. The current flowing through the inductor in the off period of the switching element is detected by using a current detection resistor, the operation mode is determined on the basis of the inductor current IL at a predetermined timing and the switching element is optimally controlled in accordance with the operation mode.

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Nagaokakyo, Japan

Yoshiyuki Uno