CN107911903A - Led drive circuit and mobile terminal - Google Patents
Led drive circuit and mobile terminal Download PDFInfo
- Publication number
- CN107911903A CN107911903A CN201711276682.9A CN201711276682A CN107911903A CN 107911903 A CN107911903 A CN 107911903A CN 201711276682 A CN201711276682 A CN 201711276682A CN 107911903 A CN107911903 A CN 107911903A
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- Prior art keywords
- current
- led
- triode
- drive circuit
- module
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
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Abstract
The invention discloses a kind of LED drive circuit, including：A kind of LED drive circuit, including：Power module, LED and current limliting module, the power module are connected with the LED and the current limliting module respectively, and the LED is connected with the current limliting module；The power module is used to export glow current, and the LED is used to be shone according to the glow current；The current limliting module is used to limit the glow current that the power module is supplied to the LED, so that the glow current is constant.Present invention also offers a kind of mobile terminal for including above-mentioned LED drive circuit.The LED drive circuit of the present invention, the glow current of the LED is flowed through by the limitation of current limliting module, makes the glow current of LED constant, and circuit is simple, cost is relatively low.
Description
Technical field
The present invention relates to light source driving circuit field, specifically, is related to a kind of LED drive circuit and mobile terminal.
Background technology
Developing with the continuous renewal of mobile terminal, requirement of the people to the various performances of mobile terminal also improves therewith,
The cost performance requirement to mobile terminal is also increasingly lifted at the same time.
The mobile terminals such as present mobile phone all can use the design of LED equipped with flash lamp and indicator light, light source, with
The product such as the use of LED, corresponding LED drivings IC comes into being.
But use the LED drive circuit cost of driving IC often higher, and the indoor design of driving IC is often DC-DC
Change (buck circuits), and Switching Power Supply needs the switching frequency of about 1MHz, so that increasing EMI on PCB (refers to electronic product
Work other electronic products on periphery can be interfered) risk.
The content of the invention
In view of defect existing in the prior art, the present invention provides a kind of easy constant-current drive circuit and mobile terminal.
In order to realize above-mentioned purpose, present invention employs following technical solution：
According to an aspect of the present invention, there is provided a kind of LED drive circuit, including：Power module, LED and current limliting mould
Block, the power module are connected with the LED and the current limliting module respectively, and the LED is connected with the current limliting module；
The power module is used to export glow current, and the LED is used to be shone according to the glow current；It is described
Current limliting module is used to limit the glow current that the power module is supplied to the LED, so that the glow current is constant.
Specifically, the current limliting module includes constant current unit and reference voltage unit, the reference voltage unit with it is described
Constant current unit connects, and the constant current unit is connected with the power module and the LED respectively；
The reference voltage unit is used to provide reference voltage to the constant current unit, and the constant current unit is used for according to institute
State reference voltage and limit the glow current.
Specifically, the constant current unit includes the first triode；
The base stage of first triode is connected with the power module, the collector of first triode with it is described
LED connections, the emitter of first triode are connected with the reference voltage unit.
Specifically, the reference voltage unit includes the second triode, the first shunt resistance and the second shunt resistance；
The first of the base stage of second triode, the first end of first shunt resistance and second shunt resistance
The emitter respectively with first triode is held to be connected, the emitter of second triode, first shunt resistance
Second end and the second end of second shunt resistance are grounded respectively, the collector of second triode and the one or three pole
The base stage connection of pipe.
Specifically, it is connected with the first current-limiting resistance between the base stage of first triode and the power module.
Specifically, it is connected with the second current limliting between the emitter of the base stage of second triode and first triode
Resistance.
Specifically, the 3rd current-limiting resistance is connected between the LED and the power module.
Specifically, the light source driving circuit further includes filter module, and the filter module is connected to the power module
Between the LED, the filter module is used to filter the glow current of power module output.
Specifically, the filter module includes capacitor, and the first end of the capacitor is connected with the power module, institute
State the second end ground connection of capacitor.
According to another aspect of the present invention, a kind of mobile terminal, including above-mentioned LED drive circuit are additionally provided.
Beneficial effects of the present invention：Compared with prior art, LED drive circuit of the invention, is limited by current limliting module
The glow current of the LED is flowed through, makes the glow current of LED constant, and circuit is simple, cost is relatively low.
Brief description of the drawings
Fig. 1 is the module map of LED drive circuit according to an embodiment of the invention；
Fig. 2 is the circuit diagram of LED drive circuit according to an embodiment of the invention.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, with reference to the accompanying drawings and embodiments, it is right
The present invention is further described.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and do not have to
It is of the invention in limiting.
Fig. 1 is the module map of LED drive circuit according to an embodiment of the invention.Fig. 2 is according to an embodiment of the invention
LED drive circuit circuit diagram.
With reference to Fig. 1, Fig. 2, LED drive circuit according to an embodiment of the invention includes power module 10, LED20 and current limliting
Module 30.Wherein, the cathode of power module 10 is connected with the cathode and current limliting module 30 of LED20 respectively.The anode and limit of LED20
Flow module 30 connects.It should be appreciated that LED drive circuit according to an embodiment of the invention can also include it is other necessary
Component.
Specifically, power module 10 is used to export glow current.Power module 10 is used to export glow current electric current.Power supply
The cathode of module 10 and the cathode of LED20 connect, to provide the operating current of forward direction for LED20.The anode of power module 10 connects
Ground.
Current limliting module 30 is connected with the cathode of power module 10.Current limliting module 30 is connected with the anode of LED20.Current limliting module
30 glow currents for being used to limit the output of power module 10 are so that the glow current for flowing through LED20 is constant.
Positive operating current and constant operating current are needed when LED20 is worked normally.LED20 is according to current limliting module
The 30 constant glow currents controlled shine.
When LED drive circuit works normally, power module 10 exports glow current.Current limliting module 30 limits the glow current
So that the glow current for flowing through LED20 is constant.LED20 shines according to the constant glow current.
A kind of embodiment according to the present invention, current limliting module 30 include constant current unit 31 and reference voltage unit 32.Base
Quasi- voltage cell 31 is connected with constant current unit 32.Constant current unit 31 connects with the cathode of power module 10 and the anode of LED20 respectively
Connect.Reference voltage unit 32 is used to provide reference voltage to constant current unit 31.Constant current unit 31 is used to be limited according to reference voltage
The glow current that power module 10 exports, so that the glow current for flowing through LED20 is constant.
Specifically, constant current unit 31 includes the first triode 311.The base stage of first triode 311 connects with power module 10
Connect.The collector of first triode 311 and the anode of LED20 connect.The emitter and reference voltage unit of first triode 311
32 connections.According to the Current amplifier characteristic of triode, when the first triode 311 works normally, collector current and base stage
Current in proportion relation.That is when the first triode 311 works normally, collector current relation proportional to base current, and
In the case that the parameters such as supply voltage, triode-type determine, the electric current of collector is invariable.And collector is gone here and there with LED20
Connection, the glow current that LED20 is flowed through in the case where collector current is constant is also invariable.Preferably, the first triode
The first current-limiting resistance 312 is connected between 311 base stage and power module 10.First current-limiting resistance 312 is the first triode 311
Base current is provided.Preferably, it is connected with the 4th current-limiting resistance 313 between the first current-limiting resistance 312 and power module 10.4th
Current-limiting resistance is used for the size of electric current in limiting circuit.It is understood that the present invention is not restricted to this, constant current unit 31 is also
Other suitable circuit structures can be used to make the glow current for flowing through LED20 constant.
Specifically, reference voltage unit 32 includes the second triode 321, the first shunt resistance 322 and the second shunt resistance
323.The first end difference of the base stage of second triode 321, the first end of the first shunt resistance 322 and the second shunt resistance 323
It is connected with the emitter of the first triode 311.The emitter of second triode 321, the second end of the first shunt resistance 322 and
The second end of two shunt resistances 323 is grounded respectively.The collector of second triode 321 is connected with the base stage of the first triode 311.
From the working characteristics of triode, when the second triode 321 works normally, the voltage between base stage and emitter is the two or three
Conducting voltage when pole pipe 321 works normally.The conducting voltage is corresponding with the type of triode.Therefore the second triode 321 is
First shunt resistance 322 and the second shunt resistance 323 provide reference voltage.That is the voltage at 322 both ends of the first shunt resistance etc.
Voltage in 323 both ends of the second shunt resistance is equal to the conducting voltage of the second triode 321.Therefore, can be normal according to LED20
Operating current needed for work, sets the first shunt resistance 322, the resistance value of the second shunt resistance 323, works normally circuit
When, the glow current for flowing through LED20 operating current required when being LED20 normal works.Preferably, second triode 322
The second current-limiting resistance 324 is connected between the emitter of base stage and the first triode 311.Second current-limiting resistance 324 is the two or three
Pole pipe 321 provides base current.It is understood that the present invention is not restricted to this, reference voltage unit 32 can also use
Other suitable circuit configurations provide reference voltage for constant current unit 31.
A kind of embodiment according to the present invention, the 3rd is connected between the cathode of LED20 and the cathode of power module 10
Current-limiting resistance 21, the 3rd current-limiting resistance 21 are used for the size for limiting the electric current for flowing through LED20.But the present invention is not restricted to this.
A kind of embodiment according to the present invention, LED drive circuit further include filter module 40.Filter module 40 is connected to
Between power module 10 and LED20.Filter module 40 is used to filter out the interference ripple in the glow current of the output of power module 10,
The glow current of output is set more to stablize.Preferably, filter module 40 includes capacitor.But the present invention is not restricted to this, filter
Ripple module 40 can also select other suitable circuit structures.
Present invention also offers a kind of mobile terminal for including above-mentioned LED drive circuit.It should be noted that according to this hair
The mobile terminal of bright embodiment can include mobile phone, tablet computer, laptop etc..But the present invention is not restricted to this.
The LED drive current of the present invention, the glow current of the LED is flowed through by the limitation of current limliting module, makes shining for LED
Electric current is constant, and circuit is simple, cost is relatively low.
The above is only the embodiment of the application, it is noted that for the ordinary skill people of the art
For member, on the premise of the application principle is not departed from, some improvements and modifications can also be made, these improvements and modifications also should
It is considered as the protection domain of the application.
Claims (10)
- A kind of 1. LED drive circuit, it is characterised in that including：Power module, LED and current limliting module, the power module point It is not connected with the LED and the current limliting module, the LED is connected with the current limliting module；The power module is used to export glow current, and the LED is used to be shone according to the glow current；The current limliting Module is used to limit the glow current that the power module is supplied to the LED, so that the glow current is constant.
- 2. LED drive circuit according to claim 1, it is characterised in that the current limliting module includes constant current unit and base Quasi- voltage cell, the reference voltage unit are connected with the constant current unit, the constant current unit respectively with the power module Connected with the LED；The reference voltage unit is used to provide reference voltage to the constant current unit, and the constant current unit is used for according to the base Quasi- voltage limits the glow current.
- 3. LED drive circuit according to claim 2, it is characterised in that the constant current unit includes the first triode；The base stage of first triode is connected with the power module, and collector and the LED of first triode connect Connect, the emitter of first triode is connected with the reference voltage unit.
- 4. LED drive circuit according to claim 3, it is characterised in that the reference voltage unit includes the two or three pole Pipe, the first shunt resistance and the second shunt resistance；The first end of the base stage of second triode, the first end of first shunt resistance and second shunt resistance point Emitter not with first triode is connected, the emitter of second triode, the second of first shunt resistance The second end of end and second shunt resistance is grounded respectively, the collector of second triode and first triode Base stage connects.
- 5. LED drive circuit according to claim 3, it is characterised in that the base stage of first triode and the electricity The first current-limiting resistance is connected between source module.
- 6. LED drive circuit according to claim 4, it is characterised in that the base stage of second triode and described the The second current-limiting resistance is connected between the emitter of one triode.
- 7. LED drive circuit according to claim 1, it is characterised in that connected between the LED and the power module There is the 3rd current-limiting resistance.
- 8. LED drive circuit according to claim 1, it is characterised in that the light source driving circuit further includes filtering mould Block, the filter module are connected between the power module and the LED, and the filter module is used for the power module The glow current of output is filtered.
- 9. LED drive circuit according to claim 8, it is characterised in that the filter module includes capacitor, the electricity The first end of container is connected with the power module, the second end ground connection of the capacitor.
- 10. a kind of mobile terminal, it is characterised in that including the LED drive circuit any one of claim 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711276682.9A CN107911903A (en) | 2017-12-06 | 2017-12-06 | Led drive circuit and mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711276682.9A CN107911903A (en) | 2017-12-06 | 2017-12-06 | Led drive circuit and mobile terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107911903A true CN107911903A (en) | 2018-04-13 |
Family
ID=61854700
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711276682.9A Pending CN107911903A (en) | 2017-12-06 | 2017-12-06 | Led drive circuit and mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107911903A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109348579A (en) * | 2018-10-29 | 2019-02-15 | 宁波耀泰电器有限公司 | A kind of LED constant current circuit |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202059637U (en) * | 2011-05-12 | 2011-11-30 | 邹杰 | LED constant current and high temperature current-limiting drive circuit using crystal triode |
| CN202135371U (en) * | 2011-07-07 | 2012-02-01 | 杭州亮尔丽光电科技有限公司 | Led lamp |
| CN203378101U (en) * | 2013-07-09 | 2014-01-01 | 京东方科技集团股份有限公司 | Light emitting diode lamp strip, backlight and display device |
-
2017
- 2017-12-06 CN CN201711276682.9A patent/CN107911903A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202059637U (en) * | 2011-05-12 | 2011-11-30 | 邹杰 | LED constant current and high temperature current-limiting drive circuit using crystal triode |
| CN202135371U (en) * | 2011-07-07 | 2012-02-01 | 杭州亮尔丽光电科技有限公司 | Led lamp |
| CN203378101U (en) * | 2013-07-09 | 2014-01-01 | 京东方科技集团股份有限公司 | Light emitting diode lamp strip, backlight and display device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109348579A (en) * | 2018-10-29 | 2019-02-15 | 宁波耀泰电器有限公司 | A kind of LED constant current circuit |
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| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20180413 |
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| RJ01 | Rejection of invention patent application after publication |