CN102858055A

CN102858055A - High-efficiency LED (light-emitting diode) driving circuit

Info

Publication number: CN102858055A
Application number: CN2012102447538A
Authority: CN
Inventors: 张新华; 张若煜
Original assignee: University of Shaoxing
Current assignee: University of Shaoxing
Priority date: 2012-07-16
Filing date: 2012-07-16
Publication date: 2013-01-02

Abstract

The invention discloses a high-efficiency LED (light-emitting diode) driving circuit which comprises a starting circuit, a reference voltage source, a VDD (voltage drain drain) regulator and LDO (low dropout regulator) circuit module, an oscillator, a BIAS circuit, an error amplifier, a CV (constant voltage) control circuit, a Tons detection circuit, a CC (constant current) control circuit, a current peak control circuit and an output stage driving circuit. According to the high-efficiency LED driving circuit, stand-by power consumption is reduced, efficiency is improved, voltage and current controlling accuracies of an LED light source are increased, less heat is generated, and reliability of LED products is improved.

Description

A kind of efficient LED drive circuit

Technical field

The present invention relates to led chip art field, special relevant with a kind of efficient LED drive circuit.

Background technology

The LED illuminating lamp self has very strong advantage as the illuminating product of a new generation: energy-conservation, brightness is high, high efficiency, life-span length, environmental protection etc., because the LED illumination waits these advantages has been arranged, and has determined the wide of market prospects, the enormous amount of demand.Each LED lamp must be equipped with a LED driving power.Wherein, the LED driving power cost for the LED street lamp accounts for 8%-10% of whole light fixture cost; The LED driving power cost of LED domestic lighting lamp accounts for 1/3rd of whole light fixture cost.

The technical barrier of LED industry is heat dissipation problem, and the main cause that the LED lamp damages is because cross cause thermal damage.Thermal source produces and comprises LED lamp itself and LED driving power.

The inventor drives LED and has done research, designs a kind of efficient LED drive circuit, and this case produces thus.

Summary of the invention

Main purpose of the present invention provides a kind of efficient LED drive circuit, the decline stand-by power consumption, and raising efficiency, the voltage and current precision control of LED power supply improves, and produces few heat, improves the reliability of LED product.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

A kind of efficient LED drive circuit comprises start-up circuit, reference voltage source, VDD regulator and LDO circuit module, oscillator, BIAS circuit, error amplifier, constant voltage CV control circuit, Tons detection circuit, constant current CC control circuit, current peak control circuit, output stage drive circuit;

Start-up circuit is connected on VDD regulator and the LDO circuit module, and reference voltage source is connected to an overvoltage crowbar; VDD regulator and LDO circuit module are connected in the BIAS circuit; Outside Enable Pin is connected on the oscillator, is connected in the Tons detection circuit by oscillator again, and the output of Tons detection circuit is connected on the constant current CC control circuit; Outside Enable Pin is connected to error amplifier simultaneously, and the output of error amplifier is connected to constant voltage CV control circuit; Outer plate choosing end is connected to the current peak control circuit, connects and detects in constant current CC control circuit and constant voltage CV control circuit; The output of overvoltage crowbar, constant current CC control circuit, constant voltage CV control circuit is connected in the output stage drive circuit by a NAND gate, and the output stage drive circuit is as the output of whole drive circuit.

The output of described Tons detection circuit is connected with output line voltage-drop compensation circuit.

After adopting such scheme, can the dropping to below the 100mW of the stand-by power consumption among the present invention, efficient can significantly promote, and reaches more than 85%.The voltage and current control precision of LED power supply can be controlled in 3%, improves the cost performance of LED product.In addition, the reduction of the stand-by power consumption of this project and the lifting of efficient with producing few heat, are conducive to the heat radiation of LED.Improve the reliability of LED product.

Description of drawings

Fig. 1 is the internal module schematic diagram of preferred embodiment of the present invention.

Embodiment

By reference to the accompanying drawings, preferred embodiment of the present invention is described in further details.

A kind of efficient LED drive circuit comprises start-up circuit 1, reference voltage source 2, VDD regulator and LDO circuit module 3, oscillator 4, BIAS circuit 5, error amplifier 6, constant voltage CV control circuit 7, Tons detection circuit 8, constant current CC control circuit 9, current peak control circuit 10, output stage drive circuit 11, output line voltage-drop compensation circuit 12.

Start-up circuit 1 is connected on VDD regulator and the LDO circuit module 3, and reference voltage source 2 is connected to an overvoltage crowbar 13.VDD regulator and LDO circuit module 3 are connected in the BIAS circuit 5.Outside Enable Pin is connected on the oscillator 4, is connected in the Tons detection circuit 8 by oscillator 4 again, and the output of Tons detection circuit 8 is connected on the constant current CC control circuit 9.Outside Enable Pin FB is connected to error amplifier 6 simultaneously, and the output of error amplifier 6 is connected to constant voltage CV control circuit 7.Outer plate choosing end CS is connected to the current peak control circuit, connects and detects in constant current CC control circuit 9 and constant voltage CV control circuit 7.The output of overvoltage crowbar, constant current CC control circuit 9, constant voltage CV control circuit 7 is connected in the output stage drive circuit 11 by a NAND gate, and output stage drive circuit 11 is as the output OUT of whole drive circuit.

The output of described Tons detection circuit 8 is connected with output line voltage-drop compensation circuit 12.

When circuit start, the VCC electrifying startup produced reference voltage and vdd voltage before this, and then BIAS circuit and LDO circuit are started working, last whole chip enable, and CC ring and CV ring are just started working.

Have two loops among the present invention and realize respectively constant current CC output and constant voltage CV output.The CC loop calculates control output cycle T sw more accordingly by the opening time Tons of diode in the sampling secondary circuit, obtains the constant duty ratio Dons of secondary circuit, thus so that constant output current.

Figure 2012102447538100002DEST_PATH_IMAGE001

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Above-described embodiment only is used for explaining inventive concept of the present invention, but not to the restriction of rights protection of the present invention, allly utilizes this design that the present invention is carried out the change of unsubstantiality, all should fall into protection scope of the present invention.

Claims

1. an efficient LED drive circuit is characterized in that: comprise start-up circuit, reference voltage source, VDD regulator and LDO circuit module, oscillator, BIAS circuit, error amplifier, constant voltage CV control circuit, Tons detection circuit, constant current CC control circuit, current peak control circuit, output stage drive circuit;

2. a kind of efficient LED drive circuit as claimed in claim 1, it is characterized in that: the output of described Tons detection circuit is connected with output line voltage-drop compensation circuit.