Fairchild Korea Semiconductor Ltd.

System General Corporation

Byung-hak Ahn

Ta-Yung Yang

Jin-Hwa Chung

Youn-woong Chung

Moon-ho Choi

Il-young Jung

Chun-Chi Chen

An adaptive over-voltage protection circuit includes an over-voltage protection reference voltage provider and an over-voltage signal output unit. The over-voltage protection reference voltage provider provides a voltage of an over-voltage protection level higher than that of an over-voltage protection voltage corresponding to an output voltage supplied to a load from among a plurality of different over-voltage protection levels as an over-voltage protection reference voltage when the output voltage reaches a range of a rated voltage of the load. The over-voltage signal output unit outputs an over-voltage signal indicating an over-voltage by comparing the over-voltage protection voltage with the over-voltage protection reference voltage.

Adaptive overvoltage protection circuit and method, and power system including the same

The present invention provides a control circuit for LED driver. A voltage-feedback circuit is coupled to LEDs to sense a voltage-feedback signal for generating a voltage loop signal. Current sources are coupled to the LEDs to control LED currents. A detection circuit is connected to sense voltages of current sources for generating a current-source loop signal in response to a minimum voltage of the current sources. Furthermore, a buffer circuit generates a feedback signal in accordance with the voltage loop signal and the current-source loop signal. The feedback signal is coupled to limit a maximum voltage of the LEDs and regulate the minimum voltage across the current sources.

High efficiency LED driver with current source regulations

Growing community of inventors

Seoul, South Korea

Byung-hak Ahn