Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Keita Kawabe

Kazuhiro Murata

Naohiko Morota

Yoshihiro Mori

Takashi Saji

Tatsuya Sakurai

Koji Suzuki

Yoshihisa Minami

A switching power supply device of the present disclosure includes a device connection state detection circuit that detects a connection state in a load device connection terminal, in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated at a connecting point between a primary winding wire of the transformer and the switching element in response to operation of a pulse signal. The waveform detection circuit compares the voltage or the current with a predetermined reference value, and outputs an output signal in response to a comparison result to an OFF terminal.

Switching power supply device

A switching power supply apparatus of the present disclosure is a device connection state detection circuit that detects a connection state in a load device connection terminal in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated in a primary winding wire or a secondary winding wire of the transformer in accordance with operation of a pulse signal, compares the detected voltage or current with a preset reference value, and outputs an output signal in accordance with a comparison result, to an OFF terminal.

Switching power supply apparatus

The switching power supply apparatus includes a transformer including a primary winding, a secondary winding, an auxiliary winding, a switching device connected to the primary winding, an output voltage generation circuit which is connected to the secondary winding and generates an output voltage, and an auxiliary power voltage generation circuit which is connected to the auxiliary winding and generates an auxiliary power voltage. The switching power supply apparatus also includes a control circuit, which operates using the auxiliary power voltage and controls a driver circuit so that an intermittent oscillation is performed when the output voltage is higher than a first output voltage, and which controls a peak of a current flowing through a switching device is lower than a peak in a normal mode, when the auxiliary power voltage is lower than a first auxiliary power voltage in the intermittent oscillation.

Switching power supply apparatus and semiconductor device

At the starting time and an overload time in which the output voltage of the switching power source apparatus is low, if an overcurrent state, in which the ON period of the switching device becomes short and a current not less than the current limit value of the switching device flows through the switching device, occurs, this overcurrent state is detected. The blanking period of a blanking pulse signal is made shorter than the blanking period that is obtained during steady operation, and the ON period of the switching device is made shorter. Hence, the device current flowing through the switching device can be made small in each pulse for the switching operation, and, at the same time, the device current is suppressed from increasing each time a pulse for the switching operation is generated.

Growing community of inventors

Osaka, Japan

Keita Kawabe