CN201860489U

CN201860489U - Automobile lighting LED drive short circuit protection circuit

Info

Publication number: CN201860489U
Application number: CN 201020570719
Authority: CN
Inventors: 李佳颖
Original assignee: Shanghai Koito Automotive Lamp Co Ltd
Current assignee: HASCO Vision Technology Co Ltd
Priority date: 2010-10-21
Filing date: 2010-10-21
Publication date: 2011-06-08
Anticipated expiration: 2020-10-21

Abstract

An automobile lighting LED drive short circuit protection circuit comprises an input voltage Vin, an output voltage Vout, an LED, an isolation circuit module, an MOS (metal oxide semiconductor) tube drive circuit module, a P-MOS tube Q1, a PWM (pulse width modulation) control chip and a feedback circuit module, wherein the input voltage Vin is sequentially connected with the isolation circuit module, the MOS tube drive circuit module, the P-MOS tube Q1 and the output voltage Vout, the feedback circuit module and the PWM control chip are connected between the output voltage Vout and the input voltage Vin so as to form a feedback loop and an LED short circuit protection circuit module connected with the LED, and the LED short circuit protection circuit module comprises a plurality of switch modules and divider modules. The automobile lighting LED drive short circuit protection circuit not only can provide the LED load with short circuit protection, but also can provide short circuit protection for the power supply aiming at the anode and the cathode of the LED.

Description

A kind of automotive lighting LED drives short-circuit protection circuit

Technical field

The utility model relates to electronic technology field, relates in particular to a kind of short-circuit protection circuit, and particularly a kind of automotive lighting LED drives short-circuit protection circuit.

Background technology

LED has that response speed is fast, low-power consumption, energy-conservation, remarkable advantage such as the life-span is long.Owing to the rapid response speed of LED, be specially adapted to the application of automobile brake lamp and direction indicator lamp, can reduce the probability of happening of traffic accidents such as rear-end collision.Along with the raising of semi-conducting material and packaging technology, the luminous flux and the light extraction efficiency of led light source improve gradually, and led light source has been widely used in special lighting fields such as traffic lights, automotive lighting, billboard.The LED Driving technique is also progressively developed along with the development of LED application technology.

Therefore LED is a kind of along with the variation by the LED current value changes the well-illuminated light emitting source of light, and LED is luminous constant if desired, and the current value of then must control flows crossing LED is constant.Usually the LED that is adopted drives the constant current method linear adjustable type and two kinds of methods of switch adjustable type.The core technology of linear regulation formula is to utilize the switching tube that works in the range of linearity to come control load as a dynamic adjustable resistance, to guarantee under the situation that input voltage changes, the power consumption that the switching tube load is different, thus the electric current that flows through the LED load is remained unchanged substantially.But this Driving technique not only is subjected to the restriction of input voltage range, and loss is very big, and efficient is very low, causes the heating problem of circuit board serious.And the switch adjustable type is that efficient is higher in the energy conversion, can reach more than 90% under the perfect condition.The core of this Driving technique is between the switching tube with quick break-make places input and exports, by regulating the mean value that break-make ratio (being duty ratio) is controlled output dc voltage, this average voltage is made of the square-wave pulse of adjustable-width, and the mean value of square-wave pulse is exactly VD.With the LC filter square-wave pulse is smoothed to the output of ripple-free direct current, its value equals the mean value of square-wave pulse.Whole switching circuit adopts negative feedback, and by detecting output voltage and controlling duty ratio in conjunction with negative feedback, regulated output voltage is not subjected to the influence of input voltage and load variations.At present, the switch adjustable type circuit of buck (BUCK), boost type (BOOST), step-down/up type (BUCK-BOOST) is widely used in domestic lighting and automotive lighting.

The LED driver module applies to the automobile lamp field, at production line or install in the wiring process be short-circuited easily, situations such as LED load line and power line wrong, cause the inefficacy and the damage of whole LED driver module.And the requirement that also has short-circuit protection to test to electric control unit in each main engine plants' standard.At present on the automobile LED market, only limit to the short-circuit protection of LED load self, i.e. short-circuit protection when LED positive pole short circuit LED negative pole at the protection of LED.But at the LED positive pole, the LED negative pole does not but relate to the short-circuit protection of power supply, seems very necessary so design a kind of solid short-circuit protection circuit at the LED driver module.

At disclosed number of patent application be: 201010151363.7; patent name is: in a kind of patent application document of LED constant current source output short circuit protection circuit; a kind of LED constant current source output short circuit protection circuit is disclosed; it comprises the LED constant-current source; micro-control unit; the PWM controller; current signal is transferred to the PWM controller successively by micro-control unit; the LED constant-current source; it comprises that one has the switching circuit of auto restore facility; described switching circuit one end with auto restore facility and described PWM controller with link to each other; the other end is connected with the LED constant-current source; in order to the realization short-circuit protection, during the circuit operate as normal, metal-oxide-semiconductor Q4; with metal-oxide-semiconductor Q3 conducting; when short circuit took place, metal-oxide-semiconductor Q4 ended, and metal-oxide-semiconductor Q3 also ends; the current cut-off of LED lamp; when short circuit was got rid of, protective circuit started restore circuit automatically, made circuit get back to operating state; the protective circuit that the utility model provides has not only been protected constant-current source, and also has auto restore facility.Also for relating to the positive pole to LED, the LED negative pole is to the short-circuit protection of power supply for it.

The utility model content

The technical problems to be solved in the utility model is: provide a kind of automotive lighting LED to drive short-circuit protection circuit; this automotive lighting LED drives short-circuit protection circuit can not only provide the short-circuit protection of LED load self, and can also provide at LED anodal and negative pole that the short circuit of power supply is protected.

In order to solve the problems of the technologies described above; the utility model provides a kind of automotive lighting LED to drive short-circuit protection circuit; it comprises input voltage vin; output voltage V out; LED; the buffer circuit module; the metal-oxide-semiconductor drive circuit module; P-MOS manages Q1; pwm chip and feedback circuit module; input voltage vin successively with the buffer circuit module; the metal-oxide-semiconductor drive circuit module; P-MOS pipe Q1 is connected with output voltage V out; described feedback circuit module and pwm chip are connected between output voltage V out and the input voltage vin; form feedback loop; described automotive lighting LED drives short-circuit protection circuit and also comprises the LED short-circuit protection circuit module that links to each other with LED, and described LED short-circuit protection circuit module comprises switch module and division module.

Drive short-circuit protection circuit according to automotive lighting LED described in the utility model, be preferably described output voltage V out through the division module of series connection and division module after ground connection GND, the dividing point in the middle of division module and the division module is connected to switch module;

The positive terminal of described LED is by ground connection GND after the division module, described division module and switch module and the switch module ground connection GND afterwards that links to each other successively;

The negative pole end of described LED is by ground connection GND after the division module, the described division module ground connection GND afterwards that links to each other with switch module.

Drive short-circuit protection circuit according to automotive lighting LED described in the utility model, being preferably described switch mould is metal-oxide-semiconductor, and described division module is a resistance.

Automotive lighting LED described in the utility model drives short-circuit protection circuit can not only provide the short-circuit protection of LED load self, and can also provide at LED anodal and negative pole that the short circuit of power supply is protected.When cancelling short circuit, circuit can recover the operate as normal loop of LED voluntarily.It is simple in structure, and is with low cost, realizes easily.

Description of drawings

Fig. 1 is the electrical block diagram that automotive lighting LED described in the utility model drives short-circuit protection circuit.

Embodiment

Below, for a more detailed description to the utility model in conjunction with the accompanying drawings with embodiment.Present embodiment only is the description to the utility model preferred forms, scope of the present utility model is not had any restriction.

Embodiment

As shown in Figure 1, drive the electrical block diagram of short-circuit protection circuit for automotive lighting LED described in the utility model.Described automotive lighting LED drives short-circuit protection circuit and comprises input voltage vin; output voltage V out; LED; buffer circuit module 1; metal-oxide-semiconductor drive circuit module 2; P-MOS manages Q1; pwm chip 4 and feedback circuit module 3; input voltage vin successively with buffer circuit module 1; metal-oxide-semiconductor drive circuit module 2; P-MOS pipe Q1 is connected with output voltage V out; described feedback circuit module 3 and pwm chip 4 are connected between output voltage V out and the input voltage vin; form feedback loop; and the LED short-circuit protection circuit module 5 that links to each other with LED, described LED short-circuit protection circuit module 5 comprises switch module 55; 56 and 57 and division module 51; 52; 53 and 54.

Preferably, described output voltage V out is through the division module 51 and the division module 52 back ground connection GND of series connection, and the dividing point in the middle of described division module 51 and the division module 52 is connected to switch module 57;

The positive terminal of described LED is by division module 53 back ground connection GND, described division module 53 and switch module 55 and the switch module 57 back ground connection GND that links to each other successively;

The negative pole end of described LED is by division module 54 back ground connection GND, ground connection GND after described division module 54 links to each other with switch module 56.

Drive short-circuit protection circuit according to automotive lighting LED described in the utility model, be preferably described

switch mould

55,56 and 57 and be metal-oxide-semiconductor, described

division module

51,52,53 and 54 is a resistance.

Claims

1. an automotive lighting LED drives short-circuit protection circuit; it comprises input voltage (Vin); output voltage (Vout); LED; buffer circuit module (1); metal-oxide-semiconductor drive circuit module (2); P-MOS manages (Q1); pwm chip (4) and feedback circuit module (3); input voltage (Vin) successively with buffer circuit module (1); metal-oxide-semiconductor drive circuit module (2); P-MOS pipe (Q1) is connected with output voltage (Vout); described feedback circuit module (3) and pwm chip (4) are connected between output voltage (Vout) and the input voltage (Vin); form feedback loop, it is characterized in that:

Described automotive lighting LED drives short-circuit protection circuit and also comprises the LED short-circuit protection circuit module (5) that links to each other with LED, and described LED short-circuit protection circuit module (5) comprises switch module (55,56 and 57) and division module (51,52,53 and 54).

2. automotive lighting LED according to claim 1 drives short-circuit protection circuit, it is characterized in that: described output voltage (Vout) is through the division module (51) and division module (52) the back ground connection (GND) of series connection, and the dividing point in the middle of division module (51) and the division module (52) is connected to switch module (57);

The positive terminal of described LED is by division module (53) back ground connection (GND), described division module (53) and switch module (55) and switch module (57) the back ground connection (GND) that links to each other successively;

The negative pole end of described LED is by division module (54) back ground connection (GND), ground connection (GND) after described division module (54) links to each other with switch module (56).

3. automotive lighting LED according to claim 1 and 2 drives short-circuit protection circuit, and it is characterized in that: described switch mould (55,56 and 57) is a metal-oxide-semiconductor.

4. automotive lighting LED according to claim 1 and 2 drives short-circuit protection circuit, it is characterized in that: described division module (51,52,53 and 54) is resistance.