CN105575338B - negative voltage protection circuit - Google Patents
negative voltage protection circuit Download PDFInfo
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- CN105575338B CN105575338B CN201610094836.1A CN201610094836A CN105575338B CN 105575338 B CN105575338 B CN 105575338B CN 201610094836 A CN201610094836 A CN 201610094836A CN 105575338 B CN105575338 B CN 105575338B
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
Abstract
The present invention provides a kind of negative voltage protection circuit.The present invention bears voltage protection circuit, including：Negative pressure output circuit, sample circuit, negative pressure conversion circuit, controller；Wherein, the output end of the negative pressure output circuit is connect with the input terminal of the sample circuit, and the output end of the sample circuit is connect with the input terminal of the negative pressure conversion circuit, and the output end of the negative pressure conversion circuit is connect with the input terminal of the controller；The negative pressure output circuit, for exporting negative pressure；The sample circuit, the negative pressure for sampling the negative pressure output circuit output, and give the negative pressure feedback to the negative pressure conversion circuit；Negative pressure conversion circuit, the negative pressure for feeding back the sample circuit is converted to positive pressure, and the positive pressure is fed back to the controller；The controller, the positive pressure for being fed back according to the negative pressure conversion circuit carry out voltage protection.The present invention realizes the overvoltage to negative pressure output circuit and under-voltage protection.
Description
Technical field
The present invention relates to LED drive circuit technical field more particularly to a kind of negative voltage protection circuits.
Background technology
Liquid crystal display on existing market is largely backlight liquid crystal display comprising liquid crystal display panel and backlight mould
Group.Since liquid crystal display panel itself does not shine, need the light source provided by backlight module normally to show image, therefore, backlight
Module becomes one of the key part and component of liquid crystal display.Backlight drive circuit in backlight module drives multiple concatenated hairs
Optical diode (Light Emitting Diode, abbreviation LED) lamp group shines, to provide backlight for liquid crystal display panel.
With the promotion of power supply and backlight technology, the voltage of backlight drive circuit output is higher and higher.Due to backlight drive
The voltage of circuit output is higher, then needs the safe distance kept bigger, but in order to meet the limitation of safe distance, therefore
When realizing LED backlight driving, it will usually add the concatenated mode of negative pressure output circuit to realize by positive voltage follower circuit, thus drop
The voltage of low positive voltage follower circuit output.
When LED drive power is unstable, the voltage signal of output can be made too high or too low, be easily damaged LED light group,
Therefore it needs to carry out overvoltage and under-voltage protection to LED light group, but is usually only directed to positive voltage follower circuit in the prior art
Overvoltage and under-voltage protection lack overvoltage and under-voltage protection for negative pressure output circuit.
Invention content
The present invention provides a kind of negative voltage protection circuit, to realize the overvoltage to the negative pressure output circuit in LED backlight module
And under-voltage protection.
The present invention provides a kind of negative voltage protection circuit, including：
Negative pressure output circuit, sample circuit, negative pressure conversion circuit, controller；
Wherein, the output end of the negative pressure output circuit is connect with the input terminal of the sample circuit, the sample circuit
Output end connect with the input terminal of the negative pressure conversion circuit, the output end of the negative pressure conversion circuit and the controller
Input terminal connects；
The negative pressure output circuit, for exporting negative pressure；
The sample circuit, the negative pressure for sampling the negative pressure output circuit output, and by the negative pressure feedback to institute
State negative pressure conversion circuit；
The negative pressure conversion circuit, the negative pressure for feeding back the sample circuit are converted to positive pressure, and will be described
Positive pressure feeds back to the controller；
The controller, the positive pressure for being fed back according to the negative pressure conversion circuit carry out voltage protection.
Negative voltage protection circuit provided by the invention, including：Negative pressure output circuit, sample circuit, negative pressure conversion circuit, control
Device；The negative pressure for being exported negative pressure output circuit by sample circuit feeds back to negative pressure conversion circuit, and converts electricity electricity by negative pressure
Negative pressure is converted to positive pressure by road, then carries out voltage protection according to the positive pressure that negative pressure conversion circuit is fed back eventually by controller,
When the voltage is not in preset first range, start voltage protection realizes to negative pressure compared to existing technologies
Voltage sample, and the positive pressure that controller is identified can be converted to, to finally realize voltage protection.
Description of the drawings
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technology description to be briefly described, it should be apparent that, the accompanying drawings in the following description is this hair
Some bright embodiments for those of ordinary skill in the art without having to pay creative labor, can be with
Obtain other attached drawings according to these attached drawings.
Fig. 1 is circuit connection diagram in LED backlight module；
Fig. 2 is the structural schematic diagram of the present invention one embodiment of negative voltage protection circuit；
Fig. 3 A are the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention；
Fig. 3 B are the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention；
Fig. 4 is the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention；
Fig. 5 is the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention；
Fig. 6 is the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention.
Specific implementation mode
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present invention
In attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is
A part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art
The every other embodiment obtained without creative efforts, shall fall within the protection scope of the present invention.
Fig. 1 is circuit connection diagram in LED backlight module.As shown in Figure 1, have in figure including multiple LED1,
LED2 ..., the LED light string of LED N.Positive voltage follower circuit exports positive pressure, and controller adopts the voltage of positive voltage follower circuit
Then sample carries out overvoltage and under-voltage protection, start overvoltage protection when sampled voltage is more than value (such as+1V) of setting, when adopting
Sample voltage starts under-voltage protection when being less than another value (such as+0.3V) of setting.But without for negative pressure output circuit
Voltage protection will be described in detail for the voltage protection of negative pressure output circuit in following embodiment of the present invention.
Fig. 2 is the structural schematic diagram of the present invention one embodiment of negative voltage protection circuit.As shown in Fig. 2, the negative pressure of the present embodiment
Circuit is protected, including：
Negative pressure output circuit, sample circuit, negative pressure conversion circuit, controller；
Wherein, the input terminal of the output end of negative pressure output circuit and sample circuit connects, the output end of sample circuit with it is negative
The input terminal of voltage conversion circuit connects, and the output end of negative pressure conversion circuit is connect with the input terminal of the controller；
Negative pressure output circuit, for exporting negative pressure；
Sample circuit, the negative pressure for sampling the output of negative pressure output circuit, and give negative pressure feedback to negative pressure conversion circuit；
Negative pressure conversion circuit, the negative pressure for feeding back sample circuit is converted to positive pressure, and positive pressure is fed back to controller；
Controller, the positive pressure for being fed back according to negative pressure conversion circuit carry out voltage protection.
Specifically, the voltage protection operating mode of controller is as follows：When the voltage that the input terminal of controller inputs is more than
When first voltage threshold value (such as 1V), controller overvoltage protection works, and LED drivings stop；When the input terminal of controller is less than the
When two voltage thresholds (such as 0.3V), controller under-voltage protection is worked, and LED drivings stop, and the input terminal of controller can only identify
Positive pressure more than 0V.
Negative pressure output circuit exports negative pressure, through over-sampling circuit, gives negative pressure feedback to negative pressure conversion circuit, negative pressure conversion electricity
The negative pressure of input is converted to positive pressure by road, and positive pressure is fed back to controller, and controller carries out voltage protection according to positive pressure, when this
When voltage is not in preset first range, that is, when being more than first voltage threshold value or being less than second voltage threshold value, start voltage
Protection.
Negative voltage protection circuit provided in this embodiment, including：Negative pressure output circuit, sample circuit, negative pressure conversion circuit, control
Device processed；The negative pressure for being exported negative pressure output circuit by sample circuit feeds back to negative pressure conversion circuit, and converts electricity electricity by negative pressure
Negative pressure is converted to positive pressure by road, then carries out voltage protection according to the positive pressure that negative pressure conversion circuit is fed back eventually by controller,
When the voltage is not in preset first range, start voltage protection realizes to negative pressure compared to existing technologies
Voltage sample, and the positive pressure that controller is identified can be converted to, to finally realize voltage protection.
Fig. 3 A are the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention.The basis of embodiment shown in Fig. 2
On, in the negative voltage protection circuit of the present embodiment, the input terminal of the controller includes first input end VSNS1 and the second input terminal
VSNS2；The output end of the negative pressure conversion circuit is connect with the first input end VSNS1 of the controller plc；
Negative voltage protection circuit further includes：
Reference power supply, the output end of the reference power supply are connect with the second input terminal VSNS2 of the controller, the base
Quasi- power supply is used for output reference voltage, so that positive pressure and the benchmark that controller feed back according to the negative pressure conversion circuit are electric
Pressure carries out voltage protection.
Specifically, an input terminal of controller receives the output voltage of negative pressure conversion circuit, another input termination
Receive the reference voltage of reference power supply output.
When the voltage of the first input end VSNS1 inputs of controller is more than the reference voltage of the second input terminal VSNS2 inputs
The first preset value when, controller overvoltage protection works, LED driving stop；When the first input end VSNS1 inputs of controller
The voltage reference voltage that is less than the second input terminal VSNS2 input the second preset value when, controller under-voltage protection is worked,
LED drivings stop, and the input terminal of controller can only identify the positive pressure more than 0V.
Negative pressure output circuit exports negative pressure, through over-sampling circuit, gives negative pressure feedback to negative pressure conversion circuit, negative pressure conversion electricity
The negative pressure of input is converted to positive pressure by road, and positive pressure is fed back to the first input end VSNS1 of controller, controller according to this just
The reference voltage of the second input terminal VSNS2 inputs is pressed to carry out voltage protection, when the voltage is more than the first preset value of reference voltage
Or when less than the second preset value, start voltage protection.
In the present embodiment, positive pressure is received by the first input end VSNS1 of controller, the second input terminal VSNS2 receives base
Quasi- voltage starts voltage protection when judging that the positive pressure is more than the first preset value of reference voltage or is less than the second preset value,
To realize the overvoltage to negative pressure output circuit or under-voltage protection.
Fig. 3 B are the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention.The basis of embodiment shown in Fig. 2
On, in the negative voltage protection circuit of the present embodiment, as shown in Figure 3B, the output end of sample circuit includes the first output end v1 and second
Output end v2；The input terminal of controller includes first input end VSNS1 and the second input terminal VSNS2；
Negative pressure conversion circuit includes：First conversion circuit, the second conversion circuit；
Wherein, the first conversion circuit includes：First resistor R1, second resistance R2 and the first power supply；First resistor R1 and
Two resistance R2 series connection, one end of first resistor R1 and one end of second resistance R2 connect at the first tie point a1, controller
First input end VSNS1 is connected at the first tie point a1；The other end of first resistor R1 is connect with the first power supply, second resistance
The other end of R2 is connected to the first output end v1 of sample circuit；
Second conversion circuit includes：First switch pipe Q1, second switch pipe Q2 and second source；The leakage of first switch pipe Q1
The second output terminal v2 connections of pole D and sample circuit, the source S of first switch pipe Q1 are connect with second source, first switch pipe
The grid G of Q1 is connect with the source S of second switch pipe Q2；The source S of second switch pipe Q2 also passes through 3rd resistor R3 and second
Power supply connects, and the drain D ground connection of second switch pipe Q2, the grid G of second switch pipe Q2 is connected to the second input terminal of controller
VSNS2。
Specifically, pass through the first electricity in the voltage value of the positive voltage of setting the first power supply output, the first conversion circuit
Hinder the resistance value of R1 and second resistance R2 so that the first input end VSNS1 of controller is maintained in preset first range, when negative
When the negative pressure of voltage follower circuit output is less than preset tertiary voltage threshold value, i.e. the electricity of the first output end v1 output of sample circuit
Pressure reduces, at this point, the voltage of the second output terminal v2 output of sample circuit also reduces, due to second source output voltage values not
Become, therefore the voltage difference of the source S of first switch pipe Q1 and drain D is more than the conducting voltage threshold value of first switch pipe Q1, therefore
First switch pipe Q1 conductings, since the voltage of second source output is by first switch pipe Q1 partial pressures, so second switch pipe Q2
Shutdown, the second input terminal VSNS2 of controller do not work；Since the voltage of the first output end v1 outputs of sample circuit subtracts
Small, since the output voltage of the first power supply is constant, the voltage at the first tie point a1 reduces, so first input end
The voltage of VSNS1 also reduces, and the voltage of first input end VSNS1 is less than second voltage threshold value, trigger controller under-voltage protection work(
Energy；When negative pressure output circuit output negative pressure be more than preset four voltage threshold when, i.e., negative pressure output circuit output negative pressure
The voltage of the second output terminal v2 outputs of sample circuit also increases when increase, the voltage of the source S and drain D of first switch pipe Q1
Difference is less than the conducting voltage threshold value of first switch pipe Q1, and the source S of the Q1 shutdowns of first switch pipe, second switch pipe Q2 connects the second electricity
Source so that the second input terminal VSNS2 of controller is pulled low to 0V, the electricity of the second input terminal VSNS2 by the Q2 conductings of second switch pipe
Pressure is less than second voltage threshold value, therefore trigger controller under-voltage protection function.
In the present embodiment, the negative pressure for being exported negative pressure output circuit by the first conversion circuit and the second conversion circuit is converted
For positive pressure so that the first input end VSNS1 of controller and the second input terminal VSNS2 is judging that it is pre- that the voltage received is not in
If the first range in, start voltage protection, to realize the overvoltage to negative pressure output circuit and under-voltage protection.
Fig. 4 is the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention.On the basis of Fig. 3 B illustrated embodiments
On, in the present embodiment, as shown in figure 4, sample circuit includes the 4th resistance R4, the 5th resistance R5 and the 6th resistance being connected in series with
R6；
Wherein, one end of the 4th resistance R4 is connected with one end of the 5th resistance R5 at the second tie point；5th resistance R5
The other end and one end of the 6th resistance R6 connected at third tie point；The other end of 4th resistance R4 is as sample circuit
Input terminal；The other end of 6th resistance R6 is grounded；
First output end v1 of the third tie point as sample circuit；Second tie point as the sample circuit second
Output end v2.
Fig. 5 is the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention.On the basis of Fig. 3 B illustrated embodiments
On, in the present embodiment, as shown in figure 5, on the basis of the above embodiments, in the present embodiment, the first conversion circuit further includes：
The 7th resistance R7 being connected in series with and the 8th resistance R8；Wherein, the other end of first resistor R1 passes through the 7th resistance R7 and first
Power supply connects；One end of 8th resistance R8 is grounded.
Specifically, VSNS1 is divided by current-limiting resistance, that is, first resistor R1 from the 7th resistance R7 and the 8th resistance R8, such as scheme
Shown in 4, the negative pressure of negative pressure voltage output by the 4th resistance R4, the 5th resistance R5 and the 6th resistance R6 to ground, sample circuit
First output end v1 samples the voltage of the 6th resistance R6, is divided from first resistor R1 and second resistance R2 at the first tie point a1,
By the voltage value, the 7th resistance R7 and the 8th resistance R8, first resistor R1 and second that set the positive voltage of the first power supply output
The resistance value of resistance R2 so that when VSNS1 is in normal negative pressure output area voltage be in default range (such as between
Between 0.3-1, occurrence is determined according to the negative pressure of output), when VSNS1 exceeds preset range, controller, which starts voltage, to be protected
Shield.
Fig. 6 is the structural schematic diagram of another embodiment of the negative voltage protection circuit of the present invention.On the basis of Fig. 3 B illustrated embodiments
On, in the present embodiment, as shown in fig. 6, the second conversion circuit, further includes：9th resistance R9, the first capacitance C1, the tenth resistance R10
With eleventh resistor R11；
Wherein, the second output terminal v2 connections that the drain D of first switch pipe Q1 passes through the 9th resistance R9 and sample circuit；The
The source S of one switching tube Q1 is connect by the first capacitance C1 with second source；
One end of tenth resistance R10 is connect with second source, the other end of the tenth resistance R10 and eleventh resistor R11's
One end is connected at the 4th tie point a4；The source S of first switch pipe Q1 is connected at the 4th tie point a4；Eleventh resistor
The other end of R11 is grounded.
Specifically, at the 4th tie point a4 the tenth resistance R10 and eleventh resistor R11 partial pressure, under normal operation,
The output voltage for the second source that the voltage of the source S of first switch pipe Q1 is 1/2, the voltage of the second output terminal of sample circuit
For negative value, the source S of first switch pipe Q1 and the voltage difference of drain D are more than the cut-in voltage of first switch pipe, second switch pipe
The source S of Q2 and the voltage difference of drain D are less than the cut-in voltage of second switch pipe, and second switch pipe is closed, and VSNS2 feet do not act as
With.
LED drive power is opened moment, and second source is powered by the first capacitance C1 to the source S of first switch pipe Q1,
The voltage of the second output terminal of sample circuit is 0, and the source electrode of second switch pipe Q2 is grounded by the opening of first switch pipe Q1 at this time,
Second switch pipe Q2 is closed, and VSNS2 feet do not work, and can prevent false triggering from protecting.
When the negative pressure of negative pressure output circuit output is more than preset four voltage threshold, the second output terminal of sample circuit
The voltage of v2 outputs is larger, the conducting voltage of the source S of first switch pipe Q1 and the voltage difference of drain D less than first switch pipe Q1
Threshold value, the Q1 shutdowns of first switch pipe, the source S of second switch pipe Q2 connect second source so that the Q2 conductings of second switch pipe will be controlled
Second input terminal VSNS2 of device processed is pulled low to 0V, and the voltage of the second input terminal VSNS2 of controller is less than second voltage threshold value,
Therefore trigger controller under-voltage protection function.
In Fig. 3 B- embodiments shown in fig. 6, the drain D of first switch pipe Q1 can also connect a capacitance, and capacitance
One end ground connection, shield to circuit.
In embodiments of the present invention, first switch pipe and second switch pipe can be MOS field-effect transistors.
It should be noted that the negative pressure conversion circuit in above-mentioned specific implementation mode can also pass through change as shown in Figure 3B
Shape circuit or equivalent circuit realize that the present invention does not limit this.
It should be noted that above-mentioned Fig. 3 A and Fig. 3 B illustrate only the specific implementation mode of several negative pressure protection voltages,
In practical applications, those skilled in the art can also realize that the present invention does not limit this by other specific implementation modes.
Finally it should be noted that：The above embodiments are only used to illustrate the technical solution of the present invention., rather than its limitations；To the greatest extent
Present invention has been described in detail with reference to the aforementioned embodiments for pipe, it will be understood by those of ordinary skill in the art that：Its according to
So can with technical scheme described in the above embodiments is modified, either to which part or all technical features into
Row equivalent replacement；And these modifications or replacements, various embodiments of the present invention technology that it does not separate the essence of the corresponding technical solution
The range of scheme.
Claims (6)
1. a kind of negative voltage protection circuit, which is characterized in that for realizing the overvoltage to the negative pressure output circuit in LED backlight module
And under-voltage protection, the negative voltage protection circuit include：
Negative pressure output circuit, sample circuit, negative pressure conversion circuit, controller；
Wherein, the output end of the negative pressure output circuit is connect with the input terminal of the sample circuit, the sample circuit it is defeated
Outlet is connect with the input terminal of the negative pressure conversion circuit, the input of the output end and the controller of the negative pressure conversion circuit
End connection；
The negative pressure output circuit, for exporting negative pressure；
The sample circuit, the negative pressure for sampling the negative pressure output circuit output, and by the negative pressure feedback to described negative
Voltage conversion circuit；
The negative pressure conversion circuit, the negative pressure for feeding back the sample circuit are converted to positive pressure, and by the positive pressure
Feed back to the controller；
The controller, the positive pressure for converting Voltage Feedback according to the negative pressure carry out voltage protection；
The output end of the sample circuit includes the first output end and second output terminal；The input terminal of the controller includes first
Input terminal and the second input terminal；
The negative pressure conversion circuit includes：First conversion circuit, the second conversion circuit；
Wherein, first conversion circuit includes：First resistor, second resistance and the first power supply；The first resistor and described
Second resistance is connected, and one end of the first resistor is connected with one end of the second resistance at the first tie point, the control
The first input end of device processed is connected at first tie point；The other end of the first resistor connects with first power supply
It connects, the other end of the second resistance is connected to the first output end of the sample circuit；
Second conversion circuit includes：First switch pipe, second switch pipe, 3rd resistor and second source；Described first opens
The drain electrode for closing pipe is connect with the second output terminal of the sample circuit, and source electrode and the second source of the first switch pipe connect
It connects, the grid of the first switch pipe is connect with the source electrode of the second switch pipe；The source electrode of the second switch pipe also passes through
The 3rd resistor is connect with the second source, the grounded drain of the second switch pipe, the grid of the second switch pipe
It is connected to the second input terminal of the controller.
2. negative voltage protection circuit according to claim 1, which is characterized in that the input terminal of the controller includes first defeated
Enter end and the second input terminal；The output end of the negative pressure conversion circuit is connect with the first input end of the controller；
The negative voltage protection circuit further includes：
Reference power supply, the output end of the reference power supply are connect with the second input terminal of the controller, and the reference power supply is used
In output reference voltage, so that controller converts the positive pressure of Voltage Feedback according to the negative pressure and the reference voltage carries out electricity
Pressure protection.
3. negative voltage protection circuit according to claim 1, which is characterized in that the sample circuit includes be connected in series with
Four resistance, the 5th resistance and the 6th resistance；
Wherein, one end of the 4th resistance is connected with one end of the 5th resistance at the second tie point；5th electricity
The other end of resistance is connected with one end of the 6th resistance at third tie point；Described in the other end of 4th resistance is used as
The input terminal of sample circuit；The other end of 6th resistance is grounded；
First output end of the third tie point as the sample circuit；Second tie point is as the sample circuit
Second output terminal.
4. negative voltage protection circuit according to claim 1, which is characterized in that first conversion circuit further includes：Series connection
The 7th resistance and the 8th resistance of connection；Wherein, the other end of the first resistor passes through the 7th resistance and described first
Power supply connects；One end of 8th resistance is grounded.
5. negative voltage protection circuit according to claim 1, which is characterized in that second conversion circuit further includes：9th
Resistance, the first capacitance, the tenth resistance and eleventh resistor；
Wherein, the drain electrode of the first switch pipe is connect by the 9th resistance with the second output terminal of the sample circuit；
The source electrode of the first switch pipe is connect by first capacitance with the second source；
One end of tenth resistance is connect with the second source, the other end of the tenth resistance and the eleventh resistor
One end be connected at the 4th tie point；The source electrode of the first switch pipe is connected at the 4th tie point；11st electricity
The other end of resistance is grounded.
6. bearing voltage protection circuit according to claim 3-5 any one of them, which is characterized in that the first switch pipe and described
Second switch pipe is field-effect transistor.
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| CN201610094836.1A CN105575338B (en) | 2016-02-22 | 2016-02-22 | negative voltage protection circuit |
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| CN107222698A (en) * | 2017-06-30 | 2017-09-29 | 深圳创维－Rgb电子有限公司 | The protection circuit and television set of television set |
| CN112992080B (en) * | 2021-02-09 | 2022-06-10 | 海信视像科技股份有限公司 | Display device and protection method thereof |
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| CN102196618A (en) * | 2010-03-16 | 2011-09-21 | 成都芯源系统有限公司 | LED illumination driving circuit and method |
| CN102842893A (en) * | 2012-08-31 | 2012-12-26 | 厦门华侨电子股份有限公司 | Short-circuit protection and control circuit for LED (Lighnt emitting Diode) strip lamp |
| WO2014107551A1 (en) * | 2013-01-04 | 2014-07-10 | Cree, Inc. | Lighting fixture with integral circuit protection |
| CN103680421A (en) * | 2013-11-21 | 2014-03-26 | 浙江龙驰科技有限公司 | LED backlight drive circuit |
| CN203552660U (en) * | 2013-11-21 | 2014-04-16 | 浙江龙驰科技有限公司 | LED backlight drive circuit |
| CN203661356U (en) * | 2013-12-10 | 2014-06-18 | 江阴旺达电子有限公司 | LED drive |
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|---|---|
| CN105575338A (en) | 2016-05-11 |
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Address after: 266100 Zhuzhou Road, Laoshan District, Shandong, No. 151, No. Patentee after: Hisense Video Technology Co.,Ltd. Address before: 266100 Zhuzhou Road, Laoshan District, Shandong, No. 151, No. Patentee before: HISENSE ELECTRIC Co.,Ltd. |