Omron Corporation

Noriyuki Nosaka

Wataru Okada

Satoshi Iwai

Takanori Ishii

Hironori Nakada

Takeo Nishikawa

Chen Chen

Gun Eto

Hironori Tauchi

Mamoru Sueki

Takuro Hashimoto

Kenji Kobayashi

Junya Mishima

Keiji Shiraishi

An overcurrent protection circuit includes a first switching element including a fourth terminal, a sixth terminal connected to a first terminal, and a fifth terminal, and a second switching element including a seventh terminal connected to the fifth terminal, an eighth terminal connected to the fourth terminal, and a ninth terminal. The first switching element electrically connects the sixth terminal and the fifth terminal in response to detecting a voltage value between the first terminal and a third terminal of the switching device exceeding a predetermined threshold based on the predetermined threshold voltage input into the fourth terminal. The second switching element electrically connects, in response to the sixth terminal and the fifth terminal of the first switching element being electrically connected to each other, the eighth terminal and the ninth terminal to lower the predetermined threshold voltage input into the fourth terminal of the first switching element.

Overcurrent protection circuit and power converter

A driving circuit that drives a switching element, the driving circuit includes: a controller that includes a first terminal connected to a gate terminal of the switching element and a second terminal connected to a source terminal of the switching element, and outputs a control signal from the first terminal to the gate terminal; a first capacitor and a first resistor connected in parallel; and a second capacitor and a second resistor connected in parallel, in which the first capacitor and the first resistor are connected in series to a first connecting wire for connecting the gate terminal and the first terminal on the gate terminal side of the first connecting wire, and in which the second capacitor and the second resistor are connected in series to the first connecting wire on the first terminal side of the first connecting wire.

Driving circuit for switching element and switching circuit

In a switching circuit apparatus, first and second capacitors apply power supply voltages to first and second drive circuits. First and second diodes are connected such that currents flow from a DC voltage source to the first and second capacitors. A resistor and a Zener diode are connected in series between a terminal and a node, such that a reverse bias voltage is applied from the terminal to the Zener diode via the resistor. A third diode is connected such that a current flows to the first capacitor from a node (N) between the resistor and the Zener diode.

Switching circuit apparatus capable of controlling multiple switching elements to synchronously turn on and off with bootstrap circuit

A driving circuit for a switching element that drives a switching element of a current-driven type. The driving circuit includes a controller including a first terminal and a second terminal and that outputs a control signal to a gate terminal of the switching element. A first resistor, which regulates a current serving as the control signal, is connected to the first terminal, and a first capacitor is connected in parallel to the first resistor. A second resistor and a second capacitor are connected in parallel, and a current path extends from the first resistor and the first capacitor to the gate terminal and from a source terminal of the switching element to the second terminal of the controller. The second resistor and the second capacitor are in the current path.

A semiconductor circuit includes: a first inductor part configured to connect in series with a source electrode of a first semiconductor element; and a second inductor part configured to connect in series with a source electrode in a second semiconductor element that is configured to connect in parallel with the first semiconductor element; the first inductor part and the second inductor part are arranged to generate an induced electromotive force in the first inductor part and the second inductor part by way of a magnetic interaction so that the currents flowing in the first inductor part and the second inductor part are reinforced in the same direction.

Semiconductor circuit

A power converter apparatus includes a switching circuit generating an AC voltage by switching a DC voltage at a predetermined switching frequency, and a filter circuit converting the AC voltage from the switching circuit into the DC voltage by low-pass filtering the AC voltage. The filter circuit includes first and second bypass capacitors, and an inductor. The first bypass capacitor bypasses noise of a first frequency component of the AC voltage from the switching circuit, and the second bypass capacitor bypasses noise of a second frequency component of the AC voltage from the switching circuit, which is lower than the first frequency component. The inductor is between the first and second bypass capacitors, and the inductance thereof is set so that a resonance frequency of the filter circuit is lower than multiple times the switching frequency by insertion of the inductor, thereby reducing the switching noise flowing to the load.

Power converter apparatus provided with low-pass filter circuit for reducing switching frequency components

A voltage balance circuit including first and second semiconductor devices connected in series with each other is provided with a first transformer having a primary winding and a secondary winding, a second transformer having a primary winding and a secondary winding. A pair of capacitors connected in series with each other and connected between the output terminals of the plurality of semiconductor devices. A first control signal is applied to the control electrode of the first semiconductor device via the primary winding of the first transformer. A second control signal is applied to the control electrode of the second semiconductor device via the primary winding of the second transformer, with one end of each secondary winding connected to each other.

Voltage balance circuit for semiconductor devices connected in series with each other, switching circuit, and power converter apparatus

An overcurrent protection circuit is provided for a switching element turned on/off based on a control voltage. The overcurrent protection circuit includes a first transistor and a second transistor. The first transistor is a PNP bipolar transistor and has an emitter connected to the control voltage. The second transistor is an NPN bipolar transistor and has a base connected to a collector of the first transistor, a collector connected to a base of the first transistor and pulled up to a predetermined pull-up voltage, and a grounded emitter. When the control voltage exceeds a predetermined first threshold voltage, the first and second transistors are turned on, the control voltage is dropped by drop of the pull-up voltage, and thus the overcurrent protection circuit starts a protection operation of turning off the switching element.

Overcurrent protection circuit for switching element turned on and off based on control voltage

A driver circuit controls a first switch element. A first resistor is connected between the driver circuit and the first switch element. A second switch element is connected to the first switch element. An overcurrent detector circuit controls the second switch element based on an overcurrent current flowing through the first switch element. A second resistor is connected between the overcurrent detector circuit and the second switch element. The first and second resistor is set such that a turn-off time of the first switch element when the second switch element is turned on by the overcurrent detector circuit is longer than a turn-off time of the first switch element when the first switch element is turned off by the driver circuit.

Switch circuit capable of overcurrent protection with small and simple circuit, and with simple operation, without affecting normal operation

A power converter apparatus is provided to include a switching circuit, and a filter circuit. The switching circuit generates an AC voltage by switching a DC voltage at a predetermining switching frequency, and the filter circuit converts the AC voltage from the switching circuit into the DC voltage by low-pass filtering the AC voltage. The filter circuit induces first and second bypass capacitors, and an inductor. The first bypass capacitor bypasses noise of a first frequency component of the AC voltage from the switching circuit, and the second bypass capacitor bypasses noise of a second frequency component of the AC voltage from the switching circuit, which is lower than the first frequency component. The inductor is inserted between the first and second bypass capacitors, and the inductance thereof is set so that a resonance frequency of the filter circuit is lower than the switching frequency by insertion of the inductor.

A switching elementhas a gate terminal connected to an output end Vout of a driving circuitvia a capacitorand a resistorconnected in parallel. The switching elementhas a source terminal connected to the driving circuitvia a capacitorand a Zener diodeconnected in parallel. The Zener diodehas an anode terminal connected to the source terminal of the switching elementand a cathode terminal connected to the driving circuit

Driving circuit for switching element, and switching circuit

A switching elementhas a gate terminal connected to an output endof a driving circuitvia a capacitorand a resistorconnected in parallel. The switching elementhas a source terminal connected to the driving circuitvia a capacitor. A diodeconnected in series with a resistorhas a cathode terminal connected to a section between the capacitorand the resistor, and the gate terminal and an anode terminal connected, via the resistor, to a section between the source terminal and the capacitor

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Nara, Japan

Noriyuki Nosaka