Rohm Co., Ltd.

Tetsuo Tateishi

Yuhei Yamaguchi

Genki Tsuruyama

Shingo Hashiguchi

Isao Takobe

Seiji Takenaka

Masashi Nagasato

Hiroto Oshita

Yosuke Fukumoto

Takeshi Nagata

Yasunori Muramatsu

Yoju Imamura

Kiyotaka Umemoto

Shun Fukushima

Kosuke Sato

A pulse control devicecomprises: a switch output unitwhich generates a pulse output voltage Vo from a direct-current input voltage Vi and supplies the pulse output voltage Vo to a load (such as a relay coilof a mechanical relay); a low-pass filter unitwhich receives a feedback input of the pulse output voltage Vo and generates a feedback voltage Vfb; and an output feedback control unitwhich receives an input of the feedback voltage Vfb and controls the switch output unitso that an average value of the pulse output voltage Vo becomes constant. The low-pass filter unitmay be configured without a coil.

Pulse control device

This switching power sourcehas: a switching output circuitwhich drives an inductor current IL by turning on and off an upper switchand a lower switchand generates an output voltage VOUT from an input voltage PVDD; a lower current detection unitwhich detects the inductor current IL flowing through the lower switchduring an ON-period of the lower switchand acquires lower current feedback information Iinfo; an error amplifierwhich outputs voltage feedback information Vinfo including information on an error between the output voltage VOUT (feedback voltage FB) and a reference voltage REF; an information synthesis unitthat generates synthesis feedback information VIinfo by synthesizing Iinfo with Vinfo; and an information holding unitwhich samples Vinfo during the ON-period of the lower switch

Switching power supply, semiconductor integrated circuit device, and differential input circuit

A switching power supply device includes a first switch with a first terminal connectable to an application terminal for the input voltage and a second terminal connectable to the first terminal of an inductor; a second switch with a first terminal connectable to the first terminal of the inductor and a second terminal connectable to an application terminal for a voltage lower than the input voltage; a third switch with a first terminal connectable to the first terminal of the inductor and a second terminal connectable to the second terminal of the inductor; a detector; and a controller. The controller produces, after occurrence or a sign of occurrence of an overshoot in the output voltage is detected by the detector until settlement of the overshoot in the output voltage, a control state in which to keep the first and second switches off and the third switch on.

Switching power supply device

A switching regulator control circuit is used in a switching regulator that converts an input voltage into an output voltage by the switching of a switching device, and generates a switching signal for controlling the ON/OFF operation of the switching device. The switching regulator control circuit has a fault detector and a fault protector. The fault detector detects, based on the duty ratio of the switching signal or a variable correlated to it and included in a control signal used to generate the switching signal, a fault state where the duty ratio falls outside the normal modulation range. The fault protector stops the switching of the switching device when the fault detector detects a fault state.

Switching regulator provided with a fault protector

A linear power supply circuit according to the present invention is provided with: an output transistor provided between an input end to which an input voltage is applied and an output end to which an output voltage is applied; and a driver for driving the output transistor on the basis of the difference between a voltage based on the output voltage and a reference voltage. The driver is provided with: a differential amplifier for outputting a voltage according to the difference between the voltage based on the output voltage and the reference voltage; a capacitor one end of which has an output of the differential amplifier applied thereto and the other end of which has the voltage based on the output voltage applied thereto; a converter for converting a voltage based on the output of the differential amplifier into an electrical current and outputting the electrical current; and an electrical current amplifier for amplifying the electrical current of the output of the converter. The supply voltage of the differential amplifier is a first constant voltage or the input voltage.

Linear power supply circuit

Switching regulator control circuit enabling fault protection operation, current-mode-control switching power supply device, and vehicle

A sequence circuit () includes a detector () that detects an occurrence of an event based on an input signal, an acceptor () that accepts the event whose occurrence has been detected by the detector, an inhibitor () that inhibits the acceptor from accepting another event for a first period using the acceptance of one event by the acceptor as a trigger, a clock pulse generator () that generates one or more clock pulses during a period after a second period shorter than the first period elapses from the start of the first period until the first period ends, a determiner () that determines a next state based on a current slate and the event accepted by the acceptor, and a latch () that latches the next state using the clock pulse. An output of the latch is the current state.

Logic circuit, sequence circuit, power supply control circuit, switching power supply device

A linear power supply circuit is provided with: an output transistor; and a driver for driving the output transistor on the basis of the difference between a voltage based on an output voltage and a reference voltage. The driver is provided with: a differential amplifier for outputting a voltage according to the difference between the voltage based on the output voltage and the reference voltage; a capacitor one end of which has an output of the differential amplifier applied thereto and the other end of which has the voltage based on the output voltage applied thereto; a converter for converting a voltage based on the output of the differential amplifier into an electrical current and outputting the electrical current; and a current amplifier for amplifying the electrical current of the output of the converter. The supply voltage of the differential amplifier is a first constant voltage or the input voltage.

There is provided a differential amplifier including: an inverting input terminal to which a first voltage is applied; a non-inverting input terminal to which a second voltage proportional to the first voltage is applied; and an offset part configured to generate a predetermined input offset voltage between the inverting input terminal and the non-inverting input terminal.

Differential amplifier

Provided is an integrated circuit package which complementarily switches on/off a MOS transistor Q(first switch) and MOS transistor Q(second switch) in accordance with an output voltage Vout, and which externally outputs a pulse signal having a fixed on-duty D during a step-up/step-down mode. The integrated circuit package has a determination unitfor determining the impedance of an external component connected to an external pin Pthat outputs the pulse signal to the exterior during the step-up/step-down mode, and determining whether the external component is a third switch on the basis of the impedance determination result.

Switching regulator and integrated circuit package

A switching power supply includes: a switching output circuit configured to generate an output voltage from an input voltage by charging a capacitor by turning on and off an output transistor; a control circuit configured to halt the driving of the switching output circuit when charging electric charge to the capacitor per switching event is limited to a lower limit value and the output voltage, or a feedback voltage commensurate therewith, is raised from a predetermined reference voltage; and a lower limit value setting circuit configured to variably control the lower limit value during the driven period of the switching output circuit. For example, the lower limit value setting circuit can increase the lower limit value with increase in the number of times of switching.

Switching power supply operable in an intermittent driving mode

A diving circuit drives an output transistor according to a control signal S. The gate of the first transistor is biased. The source of the first transistor is coupled to an internal line. In the on period of the output transistor, the voltage of the internal line is applied to a control electrode of the output transistor. A voltage correction circuit controls the internal line so as to gradually lower the voltage Vof the internal line with time.

Growing community of inventors

Kyoto, Japan

Tetsuo Tateishi