LED flashing circuit
AssigneeZhejiang Dahua Technology Co., Ltd.
InventorsQiang Ye, Yongjun Fang, Chengze Yao
Life of this patent
Estimating the term…
Abstract
A circuit for driving a light-emitting diode (LED) load and a direct current to direct current (DC-DC) converter includes a first sampling sub-circuit, a driving circuit. The first sampling sub-circuit is configured to generate a current signal representing a load current of the LED load. The driving circuit is configured to receive a brightness adjustment signal and a frequency adjustment signal; generate a first control signal, based on the current signal and the brightness adjustment signal, for controlling an output current of the DC-DC converter; and generate a second control signal, based on the frequency adjustment signal, for controlling a switching frequency of the LED load.
Claims20
A circuit for driving a light-emitting diode (LED) load and a direct current to direct current (DC-DC) converter comprising:
- a first sampling sub-circuit for generating a current signal representing a load current of the LED load;
- and
- a driving circuit configured to:
- receive a brightness adjustment signal and a frequency adjustment signal;
- generate a first control signal, based on the current signal and the brightness adjustment signal, for controlling an output current of the DC-DC converter;
- and
- generate a second control signal, based on the frequency adjustment signal, for controlling a switching frequency of the LED load,
- wherein the current signal representing the load current of the LED load is used to control the DC-DC converter to switch between a power-on state and a power-off state, and the driving circuit is further configured to:
- compare the load current with a current threshold;
- in response to a comparison result that the load current is higher than the current threshold, generate a power-off signal to control the DC-DC converter to stop supplying power to the LED load;
- and
- in response to a comparison result that the load current is not higher than the current threshold, maintain the DC-DC converter to supply power to the LED load.
A method of driving a light-emitting diode (LED) load and a direct current to direct current (DC-DC) converter comprising:
- generating, by a sampling sub-circuit, a current signal representing a load current of the LED load;
- receiving, by a driving circuit, a brightness adjustment signal and a frequency adjustment signal;
- generating, by the driving circuit, a first control signal, based on the current signal and the brightness adjustment signal, for controlling an output current of the DC-DC converter;
- and
- generating, by the driving circuit, a second control signal, based on the frequency adjustment signal, for controlling a switching frequency of the LED load,
- wherein the current signal representing the load current of the LED load is used to control the DC-DC converter to switch between a power-on state and a power-off state, and the method further comprises:
- comparing, by the driving circuit, the load current with a current threshold;
- generating, by the driving circuit, a power-off signal to control the DC-DC converter to stop supplying power to the LED load in response to a comparison result that the load current is higher than the current threshold;
- and
- maintaining, by the driving circuit, the DC-DC converter to supply power to the LED load in response to a comparison result that the load current is not higher than the current threshold.
Dependencies are inferred from the claim text.