CN209433837U - A kind of backlight control apparatus - Google Patents
A kind of backlight control apparatus Download PDFInfo
- Publication number
- CN209433837U CN209433837U CN201920293905.0U CN201920293905U CN209433837U CN 209433837 U CN209433837 U CN 209433837U CN 201920293905 U CN201920293905 U CN 201920293905U CN 209433837 U CN209433837 U CN 209433837U
- Authority
- CN
- China
- Prior art keywords
- pole
- effect tube
- energy supply
- control module
- field
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The utility model discloses a kind of backlight control apparatus.The circuit includes: energy supply control module, control chip UB1, field-effect tube QB3 and LED light bar；Energy supply control module is provided with power output end Uo, and power output end Uo is connect with the power input VCC of control chip UB1, to power to control chip UB1；The pole D of embedded field effect tube of control chip UB1 is connect with the pole S of field-effect tube QB3, and the pole G for controlling the power input VCC and field-effect tube QB3 of chip UB1 is connect；The pole D of field-effect tube QB3 and the negative terminal LED- of LED light bar connect, and it is breakdown to solve the problems, such as that the embedded field effect tube of light modulation chip caused by the generating positive and negative voltage terminal shortcircuit of load LED is easy, realizes the technical effect for improving the voltage stress of embedded field effect tube.
Description
Technical field
The utility model embodiment is related to light emitting diode (Light-Emitting Diode, LED) light regulating technology, especially
It is related to a kind of backlight control apparatus.
Background technique
LED television backlight power supply scheme generallys use the light modulation chip with DIM (light modulation) control, in such light modulation chip
It is equipped with field-effect tube, but since embedded field effect tube has certain pressure resistance limitation (usually within 100V), when backlight exports
Voltage is greater than 100V, and when there is backlight generating positive and negative voltage terminal shortcircuit, dim chip embedded field effect tube be easy it is breakdown.
Utility model content
The utility model provides a kind of backlight control apparatus, built-in field when improving LED light generating positive and negative voltage terminal shortcircuit to realize
The voltage stress of effect pipe.
The utility model embodiment provides a kind of backlight control apparatus, which includes: energy supply control module, control core
Piece UB1, field-effect tube QB3 and LED light bar；Wherein,
The energy supply control module is provided with power output end Uo, the power output end Uo and the control chip UB1
Power input VCC connection, with to the control chip UB1 power；
The pole D of the embedded field effect tube of the control chip UB1 is connect with the pole S of the field-effect tube QB3, the control
The power input VCC of chip UB1 is connect with the pole G of the field-effect tube QB3；
The pole D of the field-effect tube QB3 is connect with the negative terminal LED- of the LED light bar.
Optionally, further includes: the energy supply control module is provided with feedback end, and the feedback end and the negative terminal LED- connect
It connects, in the LED light bar short circuit, the power output end Uo stops powering to the control chip UB1.
Optionally, the energy supply control module further include: enable end EN, the enable end EN are receiving enable signal
Afterwards, the power output end Uo powers to the control chip UB1.
Optionally, the energy supply control module includes PNP triode QB2 and NPN triode QB1；
The power input pole Ui, C that the pole E of the PNP triode QB2 connects the energy supply control module connects the electricity
The power output end pole Uo, B of source control module is connected with the pole C of the NPN triode QB1；
The pole B of the NPN triode QB1 connects the enable end EN of the energy supply control module, and the pole E is connected to ground terminal
SGND。
Optionally, it is connected with resistance RB3 between the pole B of the PNP triode QB2 and the pole C of the NPN triode QB1,
Resistance RB5 is connected between the pole B of the PNP triode QB2 and the feedback end of the energy supply control module.
Optionally, electricity is connected between the pole B of the NPN triode QB1 and the enable end EN of the energy supply control module
Hinder RB1.
Optionally, be connected between the pole E and the pole B of the PNP triode QB2 resistance RB4 and clamp diode DB1's and
It is coupled structure.
Optionally, resistance RB2 and capacitor are connected between the pole E and the pole B of the NPN triode QB1 CB1's and to be coupled
Structure.
Optionally, the power input VCC connection capacitor CB5 ground connection of the control chip UB1.
Optionally, the pole the S connection resistance RB6 ground connection of the internal fet of the control chip UB1.
The utility model in the negative terminal LED- of LED light bar with the pole D of embedded field effect tube by connecting high-voltage large current
The mode of field-effect tube QB3, the embedded field effect tube for solving light modulation chip caused by the generating positive and negative voltage terminal shortcircuit of load LED hold
Easily breakdown problem realizes the technical effect for improving the voltage stress of embedded field effect tube.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of backlight control apparatus provided by the embodiment of the utility model；
Fig. 2 is the structural schematic diagram of energy supply control module provided by the embodiment of the utility model.
Specific embodiment
The utility model is described in further detail with reference to the accompanying drawings and examples.It is understood that herein
Described specific embodiment is used only for explaining the utility model, rather than the restriction to the utility model.It further needs exist for
It is bright, part relevant to the utility model is illustrated only for ease of description, in attached drawing rather than entire infrastructure.
Fig. 1 is the structural schematic diagram of backlight control apparatus provided by the embodiment of the utility model, and Fig. 2 is that the utility model is real
The structural schematic diagram of the energy supply control module of example offer is provided.Backlight control apparatus includes energy supply control module, and power supply controls mould
Block is applicable to the technical field of LED backlight light modulation, for controlling output to the driving power of LED.LED backlight, which refers to, uses LED
As the backlight of display screen, LED backlight is compared with traditional cold-cathode tube backlight, LED have low-power consumption, lower calorific value,
The features such as brightness is high, the service life is long.
With reference to Fig. 1 and Fig. 2, the present embodiment is LED backlight with LED light bar 102, and adjusts LED by backlight control apparatus
The brightness of lamp bar 102 is described in detail.
In the present embodiment, which is specifically included:
Energy supply control module 101, control chip UB1, field-effect tube QB3 and LED light bar 102.
Energy supply control module 101 is provided with power output end Uo, the power input of power output end Uo and control chip UB1
VCC connection is held, to power to control chip UB1.
The present embodiment to the implementation of energy supply control module 101 with no restriction, can be chip or setting circuit into
Row realizes that the present embodiment is described in detail for circuit is arranged and realizes energy supply control module 101.Energy supply control module 101
For being powered by its power output end Uo to control chip UB1, so that control chip UB1 can work normally.Control chip
UB1 is that light modulation chip can be used for adjusting the electric current of LED light bar 102 connected to it in normal work, thus realization pair
The brightness regulation of LED light bar 102.
Further, in order to realize the adjusting of the electric current to LED light bar 102, control chip UB1 is provided with built-in field-effect
Pipe.
The pole D (pin 3) of embedded field effect tube of control chip UB1 is connect with the pole S (source electrode) of field-effect tube QB3, is controlled
The pole G (grid) of the power input VCC (pin 4) and field-effect tube QB3 of coremaking piece UB1 are connect.
The pole D (drain electrode) of field-effect tube QB3 is connect with the negative terminal LED- of LED light bar 102.
In the present embodiment, by controlling the on-off of embedded field effect tube, the pole the D output electric current of embedded field effect tube is controlled
Size, to realize the adjusting to the electric current of LED light bar 102.
Further, if backlight output voltage is greater than 100V, in 102 anode LED+ of LED light bar and negative terminal LED- short circuit
When, become larger by the electric current of LED light bar 102, is easy so that embedded field effect tube is breakdown.The present embodiment passes through setting field-effect
Pipe QB3 solves the problems, such as this.
In the present embodiment, field-effect tube QB3 may be selected that the field-effect tube of high-voltage large current can be born.Wherein, field is imitated
Should the receiving voltage of pipe QB3 chosen generally according to the practical backlight voltage value voltage of LED light bar 102 (in the present embodiment be), lead to
Often drop volume is 0-90%, and receiving electric current flows through field-effect tube QB3 electric current when can be according to actual short is chosen, usually drop volume
70-80%.
The present embodiment will be illustrated the workflow of backlight control apparatus.Energy supply control module 101 passes through its power supply
Output end Uo is to control chip UB1 power supply (such as 12V), so that control chip UB1 can work normally.Controlling chip UB1 just
Often when work, to the end DIM (pin 2) the input PWM dim signal of control chip UB1, (wherein, the end DIM is control chip UB1
Brightness adjustment control foot commonly enters the PWM square-wave signal of 100Hz to 1KHz), embedded field effect tube and field-effect tube QB3 are with PWM
The low and high level of dim signal and shutdown is connected, thus realize back facet current with PWM square wave output, and then by adjust square wave arteries and veins
The width of punching realizes the brightness regulation to LED light bar 102.In 102 anode LED+ of LED light bar and negative terminal LED- short circuit, negative terminal
LED- voltage can rise rapidly, but since the pole the G level of field-effect tube QB3 is clamped at the output voltage of power supply output Uo,
Such as 12V, the pole S of field-effect tube QB3 is clamped at 12V-VGS (th), so that the pole D of embedded field effect tube is clamped at 12V-
VGS (th), and then play and protect embedded field effect tube not by over-voltage breakdown.Wherein, VGS (th) is the unlatching of field-effect tube QB3
Voltage threshold.
The utility model in the negative terminal LED- of LED light bar with the pole D of embedded field effect tube by connecting high-voltage large current
The mode of field-effect tube QB3, the embedded field effect tube for solving light modulation chip caused by the generating positive and negative voltage terminal shortcircuit of load LED hold
Easily breakdown problem realizes the voltage stress for improving embedded field effect tube, plays and embedded field effect tube is protected not hit by over-voltage
The technical effect worn.
On the basis of the above embodiments, in the backlight control apparatus, energy supply control module 101 is provided with feedback end,
Feedback end is connect with negative terminal LED-, in 102 short circuit of LED light bar, power output end Uo stops to control chip UB1 power supply.
The feedback voltage of negative terminal LED- is detected by setting feedback end, it is short in LED light bar 102 anode LED+ and negative terminal LED-
Lu Shi, the cutting of control energy supply control module 101 is to the power supply of control chip UB1 and the driving voltage of field-effect tube QB3, thus real
Now to the defencive function of field-effect tube QB3.
On the basis of the above embodiments, energy supply control module 101 further include: enable end EN, enable end EN are being received
After enable signal, power output end Uo powers to control chip UB1.
The control sequential for improving circuit by setting enable end EN, to reduce stand-by power consumption.
The present embodiment to the realization of feedback end and enable end EN in energy supply control module 101 with no restriction, the present embodiment
It is described in detail for the feedback end and enable end EN that circuit is realized in energy supply control module 101 are set.
Energy supply control module 101 includes PNP triode QB2 and NPN triode QB1.
The pole power input Ui, the C (current collection of the pole E (emitter) the connection energy supply control module 101 of PNP triode QB2
Pole) connection energy supply control module 101 the pole power output end Uo, B (base stage) connected with the pole C of NPN triode QB1.
The enable end EN of the pole B (base stage) the connection energy supply control module 101 of NPN triode QB1, the pole E (emitter) connection
To ground terminal SGND.
Resistance RB3, tri- pole PNP are connected between the pole B of PNP triode QB2 and the pole C (collector) of NPN triode QB1
Resistance RB5 is connected between the pole B of pipe QB2 and the feedback end of energy supply control module 101.
The present embodiment will be illustrated the workflow of backlight control apparatus.With reference to Fig. 1 and Fig. 2, in normal work,
101 power input Ui of energy supply control module (such as output voltage is 12V), inputs to the enable end EN of energy supply control module 101
High level, NPN triode QB1 is connected so that the B pole tension of PNP triode QB2 drags down, and then PNP triode QB2 is connected, electricity
Source control module 101, to control chip UB1 power supply (such as 12V), is allowed by its power output end Uo and is controlling chip UB1 just
Often work.And in 102 anode LED+ of LED light bar and negative terminal LED- short circuit, negative terminal LED- voltage can rise rapidly.Due to feedback
End is connect with negative terminal LED-, by the partial pressure of resistance RB3 and resistance RB5 so that the voltage of the pole B of PNP triode QB2 increases,
It, will be so that PNP triode QB2 be cut when the B (base stage) and E (emitter) both end voltage of PNP triode QB2 is less than conducting voltage
It is disconnected, to cut off the power supply of control chip UB1, embedded field effect tube and field-effect tube QB3 are turned off, guarantees field-effect tube QB3 not
By over-voltage breakdown.
On the basis of the above embodiments, between the pole B of NPN triode QB1 and the enable end EN of energy supply control module 101
It is connected with resistance RB1.Play the role of current limliting by the way that resistance RB1 is arranged.
On the basis of the above embodiments, resistance RB4 and clamper two are connected between the pole E and the pole B of PNP triode QB2
The parallel-connection structure of pole pipe DB1.By the way that clamp diode DB1 is arranged, the voltage of the pole B and E interpolar that prevent PNP triode QB2 is super
Out the limit value of PNP triode QB2 and cause to damage.
On the basis of the above embodiments, resistance RB2 and capacitor CB1 are connected between the pole E and the pole B of NPN triode QB1
Parallel-connection structure.By the setting of resistance RB2 and capacitor CB1, guarantee that NPN triode QB1 is worked normally.
On the basis of the above embodiments, the power input VCC connection capacitor CB5 ground connection of chip UB1 is controlled.By setting
It sets capacitor CB5 to be filtered, prevents influence of the crest voltage to field-effect tube QB3.
On the basis of the above embodiments, the pole the S connection resistance RB6 ground connection of the internal fet of chip UB1 is controlled.It is logical
The resistance value for crossing adjustment resistance RB6, also may be adjusted by the electric current of LED light bar 102.
Note that above are only the preferred embodiment and institute's application technology principle of the utility model.Those skilled in the art's meeting
Understand, the utility model is not limited to specific embodiment described here, is able to carry out for a person skilled in the art various bright
Aobvious variation, readjustment and substitution is without departing from the protection scope of the utility model.Therefore, although passing through above embodiments
The utility model is described in further detail, but the utility model is not limited only to above embodiments, is not departing from
It can also include more other equivalent embodiments in the case that the utility model is conceived, and the scope of the utility model is by appended
Scope of the claims determine.
Claims (10)
1. a kind of backlight control apparatus characterized by comprising energy supply control module, control chip UB1, field-effect tube QB3 and
LED light bar；Wherein,
The energy supply control module is provided with power output end Uo, the electricity of the power output end Uo and the control chip UB1
Source input terminal VCC connection, to power to the control chip UB1；
The pole D of the embedded field effect tube of the control chip UB1 is connect with the pole S of the field-effect tube QB3, the control chip
The power input VCC of UB1 is connect with the pole G of the field-effect tube QB3；
The pole D of the field-effect tube QB3 is connect with the negative terminal LED- of the LED light bar.
2. backlight control apparatus according to claim 1, which is characterized in that further include: the energy supply control module setting
There is feedback end, the feedback end is connect with the negative terminal LED-, in the LED light bar short circuit, the power output end Uo
Stop powering to the control chip UB1.
3. backlight control apparatus according to claim 2, which is characterized in that the energy supply control module further include: enabled
EN is held, after receiving enable signal, power output end Uo's enable end EN powers to the control chip UB1.
4. backlight control apparatus according to claim 3, which is characterized in that the energy supply control module includes tri- pole PNP
Pipe QB2 and NPN triode QB1；
The power input pole Ui, C that the pole E of the PNP triode QB2 connects the energy supply control module connects the power supply control
The power output end pole Uo, B of molding block is connected with the pole C of the NPN triode QB1；
The pole B of the NPN triode QB1 connects the enable end EN of the energy supply control module, and the pole E is connected to ground terminal SGND.
5. backlight control apparatus according to claim 4, which is characterized in that the pole B of the PNP triode QB2 and described
Resistance RB3, the pole B and the energy supply control module of the PNP triode QB2 are connected between the pole C of NPN triode QB1
Resistance RB5 is connected between feedback end.
6. backlight control apparatus according to claim 4, which is characterized in that the pole B of the NPN triode QB1 and described
Resistance RB1 is connected between the enable end EN of energy supply control module.
7. backlight control apparatus according to claim 4, which is characterized in that the pole E and the pole B of the PNP triode QB2 it
Between be connected with the parallel-connection structure of resistance RB4 and clamp diode DB1.
8. backlight control apparatus according to claim 7, which is characterized in that the pole E and the pole B of the NPN triode QB1 it
Between be connected with the parallel-connection structure of resistance RB2 and capacitor CB1.
9. backlight control apparatus according to claim 1, which is characterized in that the power input of the control chip UB1
VCC connection capacitor CB5 ground connection.
10. backlight control apparatus according to claim 1, which is characterized in that the inside field-effect of the control chip UB1
The pole the S connection resistance RB6 ground connection of pipe.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2019202078422 | 2019-02-18 | ||
| CN201920207842 | 2019-02-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209433837U true CN209433837U (en) | 2019-09-24 |
Family
ID=67978401
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920293905.0U Active CN209433837U (en) | 2019-02-18 | 2019-03-08 | A kind of backlight control apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209433837U (en) |
-
2019
- 2019-03-08 CN CN201920293905.0U patent/CN209433837U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205408228U (en) | LED stroboscopic lamp controller | |
| CN104427699B (en) | LED signal lamp and its LED drive circuit | |
| CN106322321A (en) | LED illumination down lamp with protection constant current drive | |
| CN204887621U (en) | LED drive power supply's excess temperature protection circuit | |
| CN103345903A (en) | LED backlight system and display device | |
| CN103533707B (en) | Voltage-stabilization dimmable LED (light emitting diode) driving power supply circuit | |
| CN105050295A (en) | Over-temperature protection circuit of light-emitting diode (LED) drive power supply | |
| CN204127737U (en) | Smart bluetooth audio amplifier LED down | |
| CN209488866U (en) | The low-voltage protection circuit of emergency light and the emergency light for applying it | |
| CN110366291A (en) | With more specification light source load Auto-matchings for electric drive, lamps and lanterns and driving method | |
| CN108430140A (en) | A kind of PWM modulation LED drive circuit with power failure memory function | |
| CN209433837U (en) | A kind of backlight control apparatus | |
| CN106354075A (en) | Control circuit of remote controller with backlight screen | |
| CN104427692A (en) | Light-controlled automatic switch circuit and lamp | |
| CN205793524U (en) | There is the dimming drive power of auxiliary power supply | |
| CN103547044A (en) | Voltage stabilizing circuit of LED energy-saving lamp constant-current boost power supply | |
| CN209571032U (en) | A kind of light alarm | |
| CN104427686A (en) | Lamp and control circuit thereof | |
| CN104066221A (en) | Optical detection circuit and light fixture | |
| CN207219110U (en) | A kind of low power loss constant LED driver | |
| CN103369764B (en) | A LED driving circuit and a LED lamp | |
| CN201965888U (en) | LED (Light Emitting Diode) screen driving device | |
| CN205546040U (en) | Automatic pressure regulating LED control circuit | |
| CN201976304U (en) | Multichannel light emitting diode driving system | |
| CN206237643U (en) | A kind of linear constant current controls LED |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |