Light-emitting diode driving circuit
AssigneePowerX Semiconductor Corporation
InventorTe Cheng Chen
Life of this patent
Estimating the term…
Abstract
A light-emitting diode driving circuit is electrically connected to the light-emitting diode array which includes a plurality of light strings. The light-emitting diode driving circuit includes a constant current source, a plurality of resistor, a detection circuit and a determination circuit. The constant current source is electrically connected between the light strings and the second current source and configured to control a driving current as a constant current. First terminals of the resistors are respectively connected to the light strings, and the second terminals of the resistors are connected to a reference voltage. The determination circuit is configured to output a failure determination signal.
Claims20
A light-emitting diode driving circuit, electrically connected to a light-emitting diode array, wherein the light-emitting diode array comprises a plurality of light strings, each of the light strings comprises a plurality of light-emitting diodes, the light strings are connected to a first current terminal to receive a driving current from the first current terminal, and the light-emitting diode driving circuit comprises:
- a constant current source, electrically connected between the light strings and a second current terminal, configured to control the driving current as a constant current;
- a plurality of resistors comprising first terminals electrically connected to the light strings respectively and second terminals electrically connected a reference voltage;
- a detection circuit, electrically connected between the resistors and the light strings, comprising a plurality of diode units, wherein each of the diode units comprises a first diode and a second diode connected in series;
- and
- a determination circuit comprising:
- a first comparator comprising a first first input terminal electrically connected to the first diodes, a first second input terminal configured to receive a first floating voltage, and a first output terminal configured to output a first determination signal;
- and
- a second comparator comprising a second first input terminal electrically connected to the second diodes, a second second input terminal configured to receive a second floating voltage, and a second output terminal configured to output a second determination signal,
- wherein the first floating voltage and the second floating voltage vary with the reference voltage.
A light-emitting diode driving circuit, electrically connected to a light-emitting diode array, wherein the light-emitting diode array comprises a plurality of light strings, each of the light strings comprises a plurality of light-emitting diodes, the light strings are electrically connected to a first current terminal to receive a driving current from the first current terminal, and the light-emitting diode driving circuit comprises:
- a constant current source, electrically connected between the light strings and a second current terminal, configured to control the driving current as a constant current;
- a plurality of resistors comprising first terminals electrically connected to the light strings respectively and second terminals electrically connected to a reference voltage;
- a detection circuit, electrically connected between the resistors and the light strings, comprising a plurality of diodes, wherein anode terminals of the diodes are configured to receive a bias direct current, and cathode terminals of the diodes are electrically connected to the resistors respectively;
- and
- a comparator comprising a first input terminal electrically connected to the anode terminals of the diodes, a second input terminal configured to receive a floating voltage, and an output terminal configured to output a determination signal, wherein the floating voltage varies with the reference voltage.
A light-emitting diode driving circuit, electrically connected to a light-emitting diode array, wherein the light-emitting diode array comprises a plurality of light strings, each of the light strings comprises a plurality of light-emitting diodes, the light strings are electrically connected to a first current terminal to receive a driving current from the first current terminal, and the light-emitting diode driving circuit comprises:
- a constant current source, electrically connected between the light strings and a second current terminal, configured to control the driving current as a constant current;
- a plurality of resistors comprising first terminals electrically connected to the light strings respectively and second terminals electrically connected to a reference voltage;
- a detection circuit, electrically connected between the resistors and the light strings, comprising a plurality of diodes, wherein cathode terminals of the diodes are configured to receive a bias direct current, and anode terminals of the diodes are electrically connected to the resistors respectively;
- and
- a comparator comprising a first input terminal electrically connected to the cathode terminals of the diodes, a second input terminal configured to receive a floating voltage, and an output terminal configured to output a determination signal, and the floating voltage varies with the reference voltage.
Dependencies are inferred from the claim text.