Patent ID: 8344661

Claim:
An LED device with simultaneous open and short detection function, the LED device comprising: a plurality of LED strings, each LED string having a positive electrode and a negative electrode; a voltage converter, coupled to the positive electrodes of the plurality of LED strings, for converting a first voltage to a second voltage according to a voltage control signal; a current driving unit, coupled to the negative electrodes of the plurality of LED strings, for providing a plurality of driving currents to the plurality of LED strings; a loop control unit, coupled to the plurality of LED strings and the voltage converter, for generating the voltage control signal according to negative electrode voltages of the plurality of LED strings; an open detector, coupled to the plurality of LED strings and the loop control unit, for performing LED open detection on the plurality of LED strings according to the negative electrode voltages of the plurality of LED strings; a short detector, coupled to the plurality of LED strings and the loop control unit, for performing LED short detection on the plurality of LED strings according to the negative electrode voltages of the plurality of LED strings; and a voltage detector, coupled to the open detector, the short detector and the voltage converter, for generating a reset signal to the short detector for restarting the LED short detection on the plurality of LED strings according to level variation of the second voltage when the open detector detects LED open occurring on the plurality of LED strings.