Protection circuit and led driving circuit
AssigneeShenzhen China Star Optoelectronics Technology Co., Ltd.
InventorsYong YANG, Fangyun LIU
Life of this patent
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Abstract
A protection circuit and an LED driving circuit are provided, which include a Zener diode, a potential dividing unit, a first switch unit, and a second switch unit. The cathode and anode of the Zener diode are connected to the first power source and an input terminal of the potential dividing unit, respectively. The control terminal, input terminal, and output terminal of the first switch unit are connected to the output terminal of the potential dividing unit, the second power source, and the control terminal of the second switch unit, respectively. The input terminal and output terminal of the second switch unit are connected to the second power source and the boost circuit, respectively.
Claims19
A protection circuit, comprising:
- a Zener diode, a potential dividing unit, a first switch unit, and a second switch unit;
- a cathode of the Zener diode is connected to the first power source and an anode of the Zener diode is connected to an input terminal of the potential dividing unit;
- the first switch unit has a control terminal connected to an output terminal of the potential dividing unit, an input terminal connected to the second power source, and an output terminal connected to a control terminal of the second switch unit, and under control of a first control signal outputted by the output terminal of the potential dividing unit, the first switch unit is configured to output a second control signal to the control terminal of the second switch unit;
- the second switch unit has an input terminal connected to the second power source and an output terminal connected to the boost circuit, the second switch unit is configured to output a voltage to the boost circuit under control of the second control signal;
- the boost circuit comprises an LED driving chip, the output terminal of the second switch unit is connected to a start terminal of the LED driving chip, the boost circuit has an input terminal connected to the first power source for pulling up a voltage outputted by the first power source;
- the potential dividing unit comprising a first resistor and a second resistor;
- the first resistor has a first terminal connected to the anode of the Zener diode, and a second terminal connected to a first terminal of the second resistor and the control terminal of the first switch unit, the second resistor has a grounded second terminal.
A protection circuit, comprising:
- a Zener diode, a potential dividing unit, a first switch unit, and a second switch unit;
- a cathode of the Zener diode is connected to the first power source and an anode of the Zener diode is connected to an input terminal of the potential dividing unit;
- the first switch unit has a control terminal connected to an output terminal of the potential dividing unit, an input terminal connected to the second power source, and an output terminal connected to a control terminal of the second switch unit, and under control of a first control signal outputted by the output terminal of the potential dividing unit, the first switch unit is configured to output a second control signal to the control terminal of the second switch unit;
- the second switch unit has an input terminal connected to the second power source and an output terminal connected to the boost circuit, the second switch unit is configured to output a voltage to the boost circuit under control of the second control signal.
An LED driving circuit, which comprises a protection circuit and a boost circuit connected to the protection circuit, the protection circuit comprising:
- a Zener diode, a potential dividing unit, a first switch unit, and a second switch unit;
- a cathode of the Zener diode is connected to the first power source and an anode of the Zener diode is connected to an input terminal of the potential dividing unit;
- the first switch unit has a control terminal connected to an output terminal of the potential dividing unit, an input terminal connected to the second power source, and an output terminal connected to a control terminal of the second switch unit, and under control of a first control signal outputted by the output terminal of the potential dividing unit, the first switch unit is configured to output a second control signal to the control terminal of the second switch unit;
- the second switch unit has an input terminal connected to the second power source and an output terminal connected to the boost circuit, the second switch unit is configured to output a voltage to the boost circuit under control of the second control signal.
Dependencies are inferred from the claim text.