Magnachip Semiconductor, Inc.

Hae Wook Kim

Zhi Yuan Cui

Young Gi Ryu

James Jung

Julie Jang

Seung Hwan Lee

Hyun Jung Kim

In Ho Hwang

Doo Soo Shin

Youn Ggi Ryu

Brent Rowe

Paul Greenland

There is provided a power supply device sensing an AC-off state. The power supply device includes a rectifier configured to rectify AC power into DC power, a transformer configured to supply output voltage by converting voltage of the DC power rectified by the rectifier, and a Pulse Width Modulation (PWM) control module configured to output voltage by switching a power switching device connected to the transformer, configured to drive the power supply device by connecting power of an HV pin to a VCC pin, and configured to determine an AC-off state by sensing voltage rectified by the rectifier.

Power supply device sensing AC-off state

A light emitting diode (LED) driving circuit includes a flicker elimination unit configured to perform a flicker removal for LED modules and a driving control unit configured to pause a procedure of the flicker removal based on an AC input voltage that is regulated through a Triode for Alternating Current (TRIAC) dimmer, so as to cause a brightness of the LED modules to be dimmed. Therefore, the LED driving circuit selectively adjusts an LED brightness level and removes LED flicker by using a TRIAC dimmer and controls the brightness level of the LED module based on a dimming level.

Light emitting diode driving circuit and lighting apparatus having the same

Provided is a switch control circuit for controlling a current control switch of a power supply, the power supply including a load, an inductor and the current control switch that are series-coupled to an input power. The switch control circuit includes a current measuring unit configured to measure a current flowing into the load, a current integral unit configured to integrate the measured current, a comparison unit configured to compare the integrated current value and a reference value and a control unit coupled to the current control switch, the control unit being configured to turn off the current control switch when the integrated current is substantially the same as the reference value and turn on the current control switch when a predefined off-time elapses from a time when the current control switch is turned off. The switch control circuit may quickly and accurately control an average current.

Switch control circuit, switch control method and converter using the same

A power converter according to examples reduces standby power consumption. The power converter includes a rectifier configured to rectify AC power into DC power, a transformer configured to output power by converting a voltage of DC power rectified by the rectifier, a PWM control module configured to control an output power by switching a power switching device connected to the transformer, a first external switch configured to provide a disable signal, a first capacitor that is connected in parallel to one side of the first external switch, a second external switch configured to provide an enable signal, and a second capacitor that is connected in parallel to one side of the second external switch.

Power converter for reducing standby power consumption

Growing community of inventors

Incheon, South Korea

Hae Wook Kim