Magnachip Semiconductor, Inc.

Doo Soo Shin

Zhi Yuan Cui

In Ho Hwang

Youn Ggi Ryu

Young Gi Ryu

Hae Wook Kim

Su Wan Park

Young Lok Shin

A switch control circuit for controlling an average current flowing into a load through a current control switch that is series-coupled to an input power and the load includes a sensing unit configured to measure a current flowing into the load, a folder unit configured to fold a sensing signal related to the measured current based on a first reference voltage to generate first and second folder output signals based on an initialization voltage, the first and second folder output signals being symmetric to each other, a comparison unit configured to compare the generated first and second folder output signals and a control unit configured to control an operation of the current control switch according to a comparison result in the comparison unit. Such a switch control circuit integrates and compares a sensing signal and a reference signal to effectively perform an average current control.

Switch control circuit and converter using 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 leakage current detection circuit includes a driving voltage detection unit that detects a cut-off point of a driving voltage regulated through a driving voltage switch, a leakage current detection unit that detects a leakage current of the driving voltage switch after cutting off of the driving voltage, generates a leakage detection signal when a driving voltage related to the leakage current exceeds a reference detection voltage and a driving voltage control unit that turns off the driving voltage switch at a cut-off point of the driving voltage to cut off the driving voltage and maintain the driving voltage switch in an off state when the leakage detection signal is received. The leakage current detection circuit detects a leakage current passing through the driving voltage switch when abnormal operation of a light emitting diode light apparatus occurs, and keeps the driving voltage switch in an off state during cutoff periods to prevent burning of the drive voltage switch.

Leakage current detection circuit, light apparatus comprising the same and leakage current detection method

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Seoul, South Korea

Doo Soo Shin