Short-circuit protection circuit of light emitting diode and short-circuit protection method thereof and light emitting diode driving apparatus using the same

An LED driving apparatus, for driving a plurality of LED strings, the LED driving apparatus comprises:

• a driving circuit, coupled to the LED strings, and configured to control a power supply of the LED strings according to a compensation voltage, wherein the driving circuit generates a feedback voltage according to a cross voltage of the LED strings and generates the compensation voltage according to a comparison result between the feedback voltage and a reference voltage;
• and
• a short-circuit protection circuit, coupled to the driving circuit and the LED strings, and configured to protect the LED strings from a short-circuit condition, the short-circuit protection circuit comprises:
• a short-circuit protection unit, configured to execute a short-circuit protection, so as to prohibit a current from flowing through the short-circuited LED string;
• and
• a control unit, coupled to the short-circuit protection unit, and configured to control the short-circuit protection unit according to one of the feedback voltage and the compensation voltage in order to determine whether to trigger the short-circuit protection;
• and
• a plurality of detection units, respectively coupled to the LED strings and respectively detecting a cathode terminal voltage of each of the LED strings when the short-circuit protection is triggered to determine whether the cathode terminal voltage of each of the LED strings is larger than a protection voltage, wherein when the detection unit corresponding to at least one the LED string of the LED strings detects that the cathode terminal voltage of the at least one LED string is larger than the protection voltage, a current is prohibited from flowing through the at least one LED string of the LED strings by the detection unit.

A method for an LED short-circuit protection, comprising:

• generating a feedback voltage according to a cross voltage of one of a plurality of LED strings;
• generating a compensation voltage according to a comparison result between the feedback voltage and a reference voltage, wherein the compensation voltage is employed to control a power supply of the LED strings;
• and
• determining whether to trigger a short-circuit protection according to at least one of the feedback voltage and the compensation voltage,
• when the short-circuit protection is triggered, respectively detecting whether a cathode terminal voltage of each of the LED strings is layer than a protection voltage, and when the cathode terminal voltage of at least one LED string among the LED strings is larger than the protection voltage, prohibiting a current from flowing through the at least one LED string of the LED strings.