Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Daijiro Arisawa

Manabu Yanagihara

Yoshihisa Minami

Takeshi Azuma

Daisuke Yamamoto

Masayasu Ito

Takanori Namba

Satoshi Kikuchi

Mikio Motomori

Tetsu Nagano

Kenichi Ishibashi

Masako Yamada

Yoshiteru Fujimoto

Akihisa Ueno

Fumihisa Watanabe

A switching circuit includes: a normally-off junction field-effect GaN transistor including source, drain, and gate terminals; a drive device of one output type electrically connected to the gate terminal; a first rectifier, between the source terminal and the gate terminal, including an anode on a source terminal side and a cathode on a gate terminal side; a capacitor between a cathode side of the first rectifier and the drive device; a first resistor between the capacitor and the drive device; a second resistor, one side of the second resistor being connected to the drive device, another side of the second resistor being connected between the cathode side of the first rectifier and the capacitor; and a second rectifier including an anode on a capacitor side and a cathode on a drive device side. No resistor is provided between the cathode side of the second rectifier and the drive device.

Switching circuit

A switching circuit includes; a switching element; a driver; a diode connected between a source terminal and a gate terminal of the switching element; a resistor connected between the driver and the gate terminal of the switching element; a series circuit connected in parallel with the resistor, and including a capacitor and a resistor; and a diode including an anode on a side of the gate terminal of the switching element and a cathode on a side of a second output terminal of the driver. The diode is connected in parallel with at least the capacitor out of the capacitor and the resistor connected in series.

When a direction command signal indicates a first direction, a signal for causing the other end of the induction load to be connected to a second power supply unit is output as a second control signal. In addition, after a passage of a first predetermined delay time after a first current detection value becomes less than a reference value of a conducting current, a signal for causing the one end of the induction load 5 to be connected to a first power supply unit is output as a first control signal. And, after a passage of a second predetermined delay time after the first current detection value becomes equal to or greater than the reference value of the conducting current, a signal for causing the one end of the induction load to be connected to the second power supply unit is output as the first control signal.

Induction load driving system

A semiconductor light source lighting circuit includes a voltage step-down unit configured to generate a drive voltage lower than an input voltage by turning on or off a first switching element in a voltage step-down mode, a voltage step-up unit configured to generate the drive voltage higher than the input voltage by turning on or off a second switching element in a voltage step-up mode, and a controller. The controller includes a charge pump unit configured to repeat charging from the drive voltage to a second capacitor and discharging from the charged second capacitor to the first capacitor in the voltage step-up mode, and a switch drive unit configured to apply a voltage higher than the voltage at the other end of the first switching element to the control terminal of the first switching element by using a voltage of the charged first capacitor.

Semiconductor light source lighting circuit and vehicular lamp

A display panel drive device includes: a ring counter circuit that includes a first ring counter having a plurality of flipflops connected in cascade, configured to operate in synchronization with a first clock signal with a first-stage one of the plurality of flipflops being set by an initial signal, and outputs signals using outputs of the plurality of flipflops; a shift register having a plurality of flipflops connected in cascade, configured to operate in synchronization with a second clock signal lower in frequency than the first clock signal with a first-stage one of the plurality of flipflops being set by the initial signal; and an output section configured to perform a logical operation between one of outputs of the ring counter circuit and one of outputs of the shift register, to generate a scanning line drive signal for a display panel.

Display panel drive device

The drive device includes a first switch section including switching elements, a second switch section including switching elements, and output circuits. Each of the output circuits includes a switching element having a first and a second end, a first voltage being supplied to the first end, and a first and a second rectifier element each having a current input terminal and a current output terminal connected to the second end of the switching element. Each of the output circuits corresponds to one of the switching elements of the first switch section and one of the switching elements of the second switch section, the one of the switching elements of the first switch section is connected to the current input terminal of the first rectifier element, and the one of the switching elements of the second switch section is connected to the current input terminal of the second rectifier element.

Drive device and display device

In a drive of a stepping motor, an electromotive force is generated on the coil of a motor with a sinusoidal wave having the same period as an energization period by smoothly rotating a rotor with microstep driving, and an induced power is stably detected by detecting the electromotive force at the zero cross of driving current. The detection around the current zero cross makes it possible to shorten a detection section, form a driving waveform with few distortions, and perform driving with a driving waveform as in an ordinary micro step. Thus a circuit is provided which is aimed at reducing noise, vibrations, and loss of synchronization, and increasing current consumption efficiency in the determination of stop.

Stepping motor driver

A device of pulse width modulation type for load drive according to the present invention includes a first output unit () that applies a first output signal (e) to a load () in response to a first drive timing signal (c), a second output unit () that applies a second output signal (f) to the load () in response to a second drive timing signal (d), a signal converter () that converts a drive input signal (a) into a parallel signal (b), the drive input signal indicating time information allowing a potential difference to be generated across the load (), and a drive timing generator () that generates the first and second drive timing signals (c, d) in response to the parallel signal (b), the load () being driven by increasing and reducing pulse widths of the first and second output signals (e, f).

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Kyoto, Japan

Daijiro Arisawa