CN203912260U - Charge control device for LED driving circuit, and LED driving circuit - Google Patents
Charge control device for LED driving circuit, and LED driving circuit Download PDFInfo
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- CN203912260U CN203912260U CN201420229074.8U CN201420229074U CN203912260U CN 203912260 U CN203912260 U CN 203912260U CN 201420229074 U CN201420229074 U CN 201420229074U CN 203912260 U CN203912260 U CN 203912260U
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- drive circuit
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- led drive
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- control device
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
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Abstract
The utility model provides a charge control device for an LED driving circuit, and the LED driving circuit. In an LED control circuit, a comparison module performs real-time detection and comparison on a constant-current turn-off voltage which decreases gradually, and if the voltage is lower than a preset voltage, a switch module is enabled to make the power supply equal to an output terminal voltage. In such a manner, charge at the output terminal of the LED driving circuit is eliminated, and the problem of display staying caused by parasitic capacitance discharge at row scanning gaps is prevented, so that the crosstalk phenomenon between upper and lower lines on the LED display screen at a high refresh rate in the prior art is prevented, and fine definition display is achieved under high refresh rate and large size conditions.
Description
Technical field
The utility model relates to LED display driver field, refers in particular to a kind of electric charge control device and LED drive circuit for LED drive circuit.
Background technology
Along with LED display is more and more widely used in our daily life and work, people are also more and more higher to the requirement of LED display, and in high-end display screen field, high refresh rate and high definition and large scale are that most of user is desired.Yet, the LED display that prior art is produced, if will reach high refresh rate and large scale often just must be sacrificed the definition that image shows, this just from the distance of high definition can be more and more away from.And the main cause that causes above-mentioned image definition variation is in prior art, the line of LED display and alignment can exist parasitic capacitance in the course of the work, and existing LED drive circuit is in the process of line scanning, electric charge in parasitic capacitance all cannot be controlled effectively, after line scanning finishes, existence due to parasitic capacitance, this row demonstration can not disappear at once, and now get started next line scanning, will produce on traditional LED display, crosstalk phenomenon between descending, if this situation of putting is paid no attention to, even if having realized high refresh rate shows, also can cause whole LED display to be subject to serious impact in the definition that shows epigraph.Therefore, be limited to parasitic capacitance in existing LED drive circuit and lack control, in prior art, also cannot meet completely the demand of simultaneously guaranteeing that in high refresh rate and large-sized situation high definition shows.
Utility model content
Technical problem to be solved in the utility model is: eliminate the parasitic capacitance producing in the line scanning process of LED display driving, thereby make LED display also can realize high definition in high refresh rate and large-sized situation, show.
In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:
For an electric charge control device for LED drive circuit, it comprises comparison module and switch module; Described comparison module is provided with predeterminated voltage input, constant current shutoff voltage input and three inputs of Enable Pin, the Enable Pin of comparison module output connecting valve module, and described switch module is serially connected with between the output and power supply of LED drive circuit;
In above-mentioned, described comparison module is comparator, the just very predeterminated voltage input of comparator, and negative pole is constant current shutoff voltage input; Described switch module is metal-oxide-semiconductor, and the grid of metal-oxide-semiconductor connects comparator output terminal, and the drain electrode of metal-oxide-semiconductor connects power supply, and source electrode connects the output of LED drive circuit;
In above-mentioned, described comparator is controlled the constant current shutoff voltage of open detection LED drive circuit according to Enable Pin, and when constant current shutoff voltage is less than the predeterminated voltage that predeterminated voltage input inputs enable switch module; Described switch module is according to the output and the power supply that enable conducting LED drive circuit;
In above-mentioned, the predeterminated voltage of described input is not more than the threshold voltage of driving tube in LED drive circuit.
The utility model also relates to a kind of LED drive circuit, it is characterized in that: it comprises electric charge control device as above;
In above-mentioned, it comprises control chip, voltage follower, driving tube and constant flow module; Described control chip output has enable signal; Described voltage follower is provided with Enable Pin, reference voltage end input and feedback end three tunnel inputs, the output of voltage follower is connected with the Enable Pin of driving tube, and one end of driving tube is output, ground connection after other end serial connection constant flow module, the driving tube other end also connects the feedback end of voltage follower.
The beneficial effects of the utility model are: in LED control circuit, by comparison module, the constant current shutoff voltage of slow decreasing is carried out detecting in real time relatively, once enable switch module lower than predeterminated voltage, make power supply identical with output end voltage, realization is carried out electric charge elimination to the output of LED drive circuit, thereby effectively avoided in line scanning gap, the demonstration causing due to parasitic capacitance discharge persists problem, and then overcome upper that in traditional sense, LED display occurs under high refresh rate, crosstalk phenomenon between descending, make to guarantee that the demand that high definition shows is achieved in high refresh rate and large-sized situation simultaneously.
Accompanying drawing explanation
Below in conjunction with accompanying drawing in detail concrete structure of the present utility model is described in detail
Fig. 1 is the concrete exemplary circuit figure of the utility model LED drive circuit.
Embodiment
By describing technology contents of the present utility model, structural feature in detail, being realized object and effect, below in conjunction with execution mode and coordinate accompanying drawing to be explained in detail.
The design of the utility model most critical is: thereby by the parasitic capacitance of each alignment of LED display being carried out to electric charge elimination to exporting the gate voltage judgement of driving tube in LED drive circuit at suitable time, to reach the object of effective elimination crosstalk phenomenon, thereby make drive circuit module realize accurate constant current control to being respectively listed as LED in LED display, greatly improved the display quality of LED display.
The utility model is a kind of electric charge control device for LED drive circuit also, and it comprises comparison module and switch module.Wherein comparison module is provided with predeterminated voltage input, constant current shutoff voltage input and three inputs of Enable Pin, the Enable Pin of comparison module output connecting valve module, and described switch module is serially connected with between the output and power supply of LED drive circuit.
From foregoing description, the beneficial effects of the utility model are: by comparison module, the constant current shutoff voltage of slow decreasing is carried out detecting in real time relatively, once enable switch module lower than predeterminated voltage, make power supply identical with output end voltage, realization is carried out electric charge elimination to the output of LED drive circuit, thereby effectively avoided in line scanning gap, the demonstration causing due to parasitic capacitance discharge persists problem, and then overcome upper that in traditional sense, LED display occurs under high refresh rate, crosstalk phenomenon between descending, make to guarantee that the demand that high definition shows is achieved in high refresh rate and large-sized situation simultaneously.
Embodiment 1:
Described comparison module is comparator, the just very predeterminated voltage input of comparator, and negative pole is constant current shutoff voltage input; Described switch module is metal-oxide-semiconductor, and the grid of metal-oxide-semiconductor connects comparator output terminal, and the drain electrode of metal-oxide-semiconductor connects power supply, and source electrode connects the output of LED drive circuit.
Embodiment 2:
Described comparator is controlled the constant current shutoff voltage of open detection LED drive circuit according to Enable Pin, and when constant current shutoff voltage is less than the predeterminated voltage that predeterminated voltage input inputs enable switch module; Described switch module is according to the output and the power supply that enable conducting LED drive circuit.
Embodiment 3:
The predeterminated voltage of described input is not more than the threshold voltage of driving tube in LED drive circuit.
In order to ensure good effect, the predeterminated voltage in this method should guarantee to export just cut-off completely of driving tube, does not have electric current to flow through, thereby the path that guarantees not leak electricity can improve the utilization ratio of power supply thus.In this technology, if do not set this voltage, but at the very start to the charging of OUT end, also there is the electric current that flows to ground in the output driving tube at LED drive circuit so, will exist power supply to arrive the path on ground, and the utilization ratio of power supply is just had a greatly reduced quality, the value of predeterminated voltage again can not be too low simultaneously, too low, the electric charge in this parasitic capacitance forms the crosstalk phenomenon between up-downgoing, and the definition that image shows will can not get effective improvement.
The utility model also provides a kind of LED drive circuit, and it comprises electric charge control device as above.
From foregoing description, the beneficial effects of the utility model are: by increase electric charge control device in LED drive circuit, thereby in the time of can making its work, the constant current shutoff voltage of slow decreasing is carried out detecting in real time relatively, once enable switch module lower than predeterminated voltage, make power supply identical with output, realization is carried out electric charge elimination to the output of LED drive circuit, thereby effectively avoided in line scanning gap, the demonstration causing due to parasitic capacitance discharge persists problem, and then overcome upper that in traditional sense, LED display occurs under high refresh rate, crosstalk phenomenon between descending, make to guarantee that the demand that high definition shows is achieved in high refresh rate and large-sized situation simultaneously.
Embodiment 1:
Described LED drive circuit includes control chip, voltage follower, driving tube and constant flow module; Described control chip output has enable signal; Described voltage follower is provided with Enable Pin, reference voltage end input and feedback end three tunnel inputs, the output of voltage follower is connected with the Enable Pin of driving tube, and one end of driving tube is output, ground connection after other end serial connection constant flow module, the driving tube other end also connects the feedback end of voltage follower.
, with regard to LED drive circuit, in conjunction with above-described embodiment, provide a concrete example herein, as shown in Figure 1,
At LED display normal scan during to n capable (corresponding Vn voltage one tunnel work), the voltage follower module of LED drive circuit is normally worked, that it exports to driving tube is a bias voltage Vg, this bias voltage Vg just makes OUT end (output) flow through constant bias current, when n line scanning finishes there is individual time slot between n+1 line scanning starts, this gap is to carry out the time that the utility model electric charge is eliminated flow process, in this gap, utilize enable signal that the control chip of LED drive circuit controls voltage follower to the comparator of electric charge control device, thereby enabling comparator starts working, voltage follower also makes its output Vg start electric discharge under this enable signal simultaneously, once the comparator of electric charge control device, Vg voltage detected and be less than predeterminated voltage Voff, just closed power supply is as shown in Figure 1 to the metal-oxide-semiconductor K of OUT end, parasitic capacitance on whole alignment is charged, until be charged to VDD level, thereby elimination electric charge, avoid, crosstalk phenomenon problem between descending.
And when LED display normal scan is capable to n+1, now voltage follower module starts normal work, bias voltage when the output Vg of voltage follower module starts to be charged to normal work by 0, in this stage, the comparator of electric charge control device does not enable, and metal-oxide-semiconductor is in open-circuit condition.
In sum, the utility model is by the analysis to the principle of the motion blur phenomenon of LED display, thereby proposed in LED display line scanning process, gate voltage and the predeterminated voltage of by judgement, exporting driving tube decide when the parasitic capacitance of each alignment of LED display is carried out to electric charge elimination, to reach the object of effective elimination crosstalk phenomenon, thereby make drive circuit module realize accurate constant current control to being respectively listed as LED in LED display, greatly improved the display quality of LED display.Implementation method of the present utility model can be used for nearly all LED display and drives in chip, and it has realized low cost, high efficiency.
The foregoing is only embodiment of the present utility model; not thereby limit the scope of the claims of the present utility model; every equivalent structure or conversion of equivalent flow process that utilizes the utility model specification and accompanying drawing content to do; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present utility model.
Claims (6)
1. for an electric charge control device for LED drive circuit, it is characterized in that: it comprises comparison module and switch module; Described comparison module is provided with predeterminated voltage input, constant current shutoff voltage input and three inputs of Enable Pin, the Enable Pin of comparison module output connecting valve module, and described switch module is serially connected with between the output and power supply of LED drive circuit.
2. the electric charge control device for LED drive circuit as claimed in claim 1, is characterized in that: described comparison module is comparator, the just very predeterminated voltage input of comparator, and negative pole is constant current shutoff voltage input; Described switch module is metal-oxide-semiconductor, and the grid of metal-oxide-semiconductor connects comparator output terminal, and the drain electrode of metal-oxide-semiconductor connects power supply, and source electrode connects the output of LED drive circuit.
3. the electric charge control device for LED drive circuit as claimed in claim 2, it is characterized in that: described comparator is controlled the constant current shutoff voltage of open detection LED drive circuit according to Enable Pin, and when constant current shutoff voltage is less than the predeterminated voltage that predeterminated voltage input inputs enable switch module; Described switch module is according to the output and the power supply that enable conducting LED drive circuit.
4. the electric charge control device for LED drive circuit as claimed in claim 3, is characterized in that: the predeterminated voltage of described input is not more than the threshold voltage of driving tube in LED drive circuit.
5. a LED drive circuit, is characterized in that: it comprises the electric charge control device as described in claim 1-4 any one.
6. LED drive circuit as claimed in claim 5, is characterized in that: it comprises control chip, voltage follower, driving tube and constant flow module; Described control chip output has enable signal; Described voltage follower is provided with Enable Pin, reference voltage end input and feedback end three tunnel inputs, the output of voltage follower is connected with the Enable Pin of driving tube, and one end of driving tube is output, ground connection after other end serial connection constant flow module, the driving tube other end also connects the feedback end of voltage follower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420229074.8U CN203912260U (en) | 2014-05-06 | 2014-05-06 | Charge control device for LED driving circuit, and LED driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420229074.8U CN203912260U (en) | 2014-05-06 | 2014-05-06 | Charge control device for LED driving circuit, and LED driving circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203912260U true CN203912260U (en) | 2014-10-29 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420229074.8U Withdrawn - After Issue CN203912260U (en) | 2014-05-06 | 2014-05-06 | Charge control device for LED driving circuit, and LED driving circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203912260U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103929864A (en) * | 2014-05-06 | 2014-07-16 | 深圳市绿源半导体技术有限公司 | Charge control method and device applied to LED drive circuit and LED drive circuit |
| CN110612659A (en) * | 2018-04-12 | 2019-12-24 | 深圳市汇顶科技股份有限公司 | Charge pump circuit and control method thereof |
-
2014
- 2014-05-06 CN CN201420229074.8U patent/CN203912260U/en not_active Withdrawn - After Issue
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103929864A (en) * | 2014-05-06 | 2014-07-16 | 深圳市绿源半导体技术有限公司 | Charge control method and device applied to LED drive circuit and LED drive circuit |
| CN103929864B (en) * | 2014-05-06 | 2015-11-25 | 深圳市绿源半导体技术有限公司 | For Charge controlled method and device, the LED drive circuit of LED drive circuit |
| CN110612659A (en) * | 2018-04-12 | 2019-12-24 | 深圳市汇顶科技股份有限公司 | Charge pump circuit and control method thereof |
| CN110612659B (en) * | 2018-04-12 | 2021-10-22 | 深圳市汇顶科技股份有限公司 | Charge pump circuit and control method thereof |
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| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20141029 Effective date of abandoning: 20151125 |
|
| C25 | Abandonment of patent right or utility model to avoid double patenting |