Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Shigenori Arai

Masato Yoshida

Shintaro Tazaki

Shinta Kato

Ryo Ichiki

Hideyuki Kihara

Yoshihito Kawakami

Kazuhisa Takada

Ryou Watabe

A switching power supply device includes: a plurality of power supply circuits which include a first power supply circuit and a second power supply circuit and respectively correspond to a plurality of phases of a multiphase AC power supply; a switching circuit; an inrush current prevention (ICP) circuit; and a control circuit. The control circuit causes the switching circuit to switch a phase to be connected to the second power supply circuit to a phase corresponding to the first power supply circuit, and causes the ICP circuit to function so that initial charge of electrolyte capacitors included in the respective power supply circuits is performed. After the initial charge is completed, the control circuit causes the switching circuit to switch the phase to be connected to the second power supply circuit to the phase corresponding to the second power supply circuit, and causes the ICP circuit to turn off.

Switching power supply device including an inrush current prevention circuit

Switching power supply device

There is provided a charging apparatus that, even when an AC adapter is connected and there is heavy load, makes it possible to reduce heat produced due to the power loss of a control transistor, reduce cost and area for implementation, and improve safety. Charging apparatushas: P-channel MOS transistors Mand Mthat control charging current; current detecting resistance Rs that is connected to current output terminals of P-channel MOS transistors Mand Mand detects the charging current; switchthat is arranged on a path that bypasses current detecting resistance Rs; and loadthat receives power supply from batterywithout involving current detecting resistance Rs when switchis closed. Current difference amplifieramplifies the detected voltage of current detecting resistance Rs, comparatorcompares the output voltage of current difference amplifierwith the reference voltage, and thereby, when current flowing into batteryis equal to or less than a predetermined value, switchis closed and current detecting resistance Rs is short-circuited.

Charging apparatus

An interface detecting circuit and interface detecting method are provided, whereby operations can be carried out depending on peripheral devices connected to USB terminals, and whereby the system can be simplified and software load can be reduced. A pull-down resistor is connected to an ID terminal of a Mini-A receptacle of a peripheral device, the voltage generated by the pull-down resistor, which is pulled down by the ID terminal of the Mini-A receptacle of the peripheral device, and a pull-up resistor, which is pulled up by the ID terminal of a Mini-B receptacle of a device, is detected in an analog fashion, using a detecting section comprised of comparators, and, via a logic section, a logic output is subjected to noise cancellation in a filter section and is memorized in a register section. The operations of other devices are determined according to the states memorized in the register section.

Interface detecting circuit and interface detecting method

Growing community of inventors

Kanagawa, Japan

Shigenori Arai