Panasonic Corporation

Panasonic Semiconductor Asia Pte. Ltd.

Yoshihito Kawakami

Masato Yoshida

Hideyuki Kihara

Atsushi Kitagawa

Shigenori Arai

Chun Kiong Leslie Khoo

Ulysses Ramos Lopez

Narciso Repollo Semira

Jiong Fu

Etsuji Sato

Junji Ishiyama

LED drivers specially directed to LED matrix driver's ghost image prevention is disclosed. The LED driver receives an external input and decodes the input to produce a time multiplex timing on turning on an LED array. The LED driver inserts a dead time to the outputs and during this time the ghost image prevention circuit discharges the output stray capacitances to a predetermined level.

LED matrix driver ghost image prevention apparatus and method

A power supply apparatus having a soft start function that enables a startup without any overshoot within an appropriate startup time regardless of whether the load is heavy or light. Even when output direct current voltage Vo has not yet risen upon startup, switch circuit () is turned ON within a count time of timer (), and clamping circuit () clamps error signal (Ve) of error amplifier (), so that an excessive signal is prevented from entering PWM circuit (), and electric power supplied to load () is controlled. Consequently, supply power as the power supply apparatus is limited, and any inrush current can be prevented from being generated. By controlling the count time of timer () when this error signal is clamped, it is possible to realize a startup within an appropriate startup time without any overshoot.

Power supply 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

Yoshihito Kawakami