Driving circuit for driving light emitting diodes and short circuit protection circuit applied to a driving circuit for driving light emitting diodes
OwnerYang-Tai Tseng, Chih-Hsiung Hsuinventors
Life of this patent
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Abstract
A short circuit protection circuit applied to a driving circuit of light emitting diodes is coupled to a highest-voltage detection circuit, a current balance circuit, and a voltage-feedback control circuit for generating a driving-current control signal and a voltage-feedback control signal according to the highest voltage of the highest-voltage detection circuit to disable the current balance circuit and the voltage-feedback control circuit so as to implement short lamp protection.
Claims12
A driving circuit for driving light emitting diodes, the driving circuit comprising:
- an alternating current voltage/direct current voltage (AC/DC) converting circuit for converting a pulse width modulation (PWM) dimming control signal to a corresponding first direct current voltage;
- a highest-voltage detection circuit for detecting a highest voltage of voltages of first terminals of a plurality of series of light emitting diodes;
- a current balance circuit for sensing and controlling driving currents flowing through the plurality of series of light emitting diodes;
- a voltage-feedback control circuit coupled to the alternating current voltage/direct current voltage converting circuit for receiving a voltage-feedback control signal to control the first direct current voltage;
- and
- a short circuit protection circuit coupled to the highest-voltage detection circuit, the current balance circuit, and the voltage-feedback control circuit for generating a driving-current control signal and the voltage-feedback control signal according to the highest voltage to disable the current balance circuit and the voltage-feedback control circuit.
A short circuit protection circuit applied to a driving circuit for driving light emitting diodes, the driving circuit including an alternating current voltage/direct current voltage converting circuit, a highest-voltage detection circuit, a current balance circuit, and a voltage-feedback control circuit, the short circuit protection circuit comprising:
- a comparator for comparing a highest voltage of the highest-voltage detection circuit with a reference voltage to generate a short circuit control signal;
- a current control circuit for generating a driving-current control signal according to the short circuit control signal;
- and
- a voltage control circuit for generating a voltage-feedback control signal according to the short circuit control signal.
Dependencies are inferred from the claim text.