CN100579325C - Light emitting diode driver as well as driving system - Google Patents
Light emitting diode driver as well as driving system Download PDFInfo
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- CN100579325C CN100579325C CN200610170231A CN200610170231A CN100579325C CN 100579325 C CN100579325 C CN 100579325C CN 200610170231 A CN200610170231 A CN 200610170231A CN 200610170231 A CN200610170231 A CN 200610170231A CN 100579325 C CN100579325 C CN 100579325C
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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
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
Abstract
The invention relates to a light emitting diode driver, in particular to a control type driver. The invention can detect the voltage demand of an application body, so that drive voltage value is automatically regulated for providing stable drive current. In addtion, set value of the drive current and output value of a direct current voltage source can be manoeuvrably regulated by that a user controls an interface for matching with the application of different requirements of voltage and electric current. Overheating phenomenon and overcurrent phenomenon, which frequently occure on the application body with high power, can also be prevented by overheating and overcurrent protection of the invention (for example, the drive current is cut off or upper limit of the drive current is set). The invention also provides a drive system, and can integrate successfully the functions for not occupy large system space. The design of the invention can also be used for stablizing power and shininess of a light emitting diode with high power used for drive illumination, a back light source and so on.
Description
Technical field
What the present invention relates to is a kind of LED drive, especially refer to a kind of control type driver (control labledriver), relevant for the automatic Drive Control Technique of adjusting driving voltage with the stabilized driving electric current, can be applicable to and drive high powers such as (backlight) is used in illumination with (lighting) and backlight light-emitting diode.
Background technology
Deciding current driver on traditional industry circle and be to have two kinds of patterns a kind of is to decide voltage system, limits the value that flows through the drive current of using body in the mode of setting voltage value; Another kind then is to decide current system, limits the value of drive current in the mode of the value of setting current source.Be depicted as 2A figure and decide voltage system (the application body of being given an example among the figure is a light-emitting diode), external input voltage VDD produces electric current I LED via LED controller 210 output voltage V LED driven for emitting lights diodes earlier; Simultaneously, described LED controller is controlled the voltage drop Vset on the electricity group R that connects with light-emitting diode in addition, relies on the value of stablizing setting voltage Vset to come steady resistance R to go up the current value (also being the current value I LED on the light-emitting diode) of circulation.Second kind for to decide current system shown in 2B figure, and the direct driven for emitting lights diode of external input voltage VLED produces electric current I LED; Simultaneously, another external input voltage VDD produces a circulation via LED controller 220 and sets reference current on the resistance R set, relies on described reference current to lock current value I LED on the light-emitting diode.Yet, for some accurate application bodies (for example-illumination of high wattage with or the backlight light-emitting diode) for, the disturbance (fluctuation) of the luminous temperature rising that causes, driving voltage and the similarities and differences of light-emitting diode material properties all can influence its drive current and can not keep to normality a fixed value.
In addition, utilizing a reference current source (reference current source) to come strangulation (clamp) drive current by current mirror (current mirror) also is a kind of method of direct Control current.Shown in 6A figure, two is 1 equally: current mirror 611,612 superpositions of N ratio amplification reference current source Iref together can be with the value of drive current ILED strangulation at N*Iref.Yet utilize two 1: the shared space all too of the current mirror of N ratio is big; Simultaneously, the practice of strangulation drive current can only be dealt with a spot of current fluctuation, for using the contingent electrical variation of the body change of equivalent resistance, current-voltage relation curve I-Vcurve and chemistry and physical characteristic (for example-) and even whole driver being caused the poverty-stricken of voltage requirements (voltage desire), traditional current mirroring circuit can not be dealt with the situation of such complexity.
Summary of the invention
The objective of the invention is to be to provide the control type driver and the drive system of a kind of high stability of light-emitting diode.Except strangulation (clamping) technology of deciding electric current, unique voltage regulator (voltage adjuster) technology can be regulated the driving voltage of using body automatically, use body the time even make, the driving current value that the driving voltage after the adjusting also can stabilized driving sets in the face of the circuit load that temperature or emergency situations caused that may raise.Drive system of the present invention is successfully to integrate above-mentioned functions, but need not take too many system space, is fit to be applied in the various portable devices.
Again, cooperate the voltage regulator technology of uniqueness of the present invention, be subjected to the variable voltage source (adjustable-voltage source) of user's interface control more to deepen range of application of the present invention; In the present invention, the user can directly choose the driving voltage that the different application body is suitable for by the described variable voltage source of control interface (control interface) control.In addition; use and the superheating phenomenon (over-temperature) and overcurrent (over-current) phenomenon of backlight for the illumination of high wattage with normal generations such as light-emitting diodes; also be provided with overtemperature protection and overcurrent protection among the present invention, for directly preventing using the serious damage of body at driving control system.
For achieving the above object, the technical solution used in the present invention is, a kind of LED drive at first is provided, and produces the stabilized driving electric current between the high cold end of using body for driving, and it comprises:
A dc supply input is for input direct voltage;
One first field-effect transistor is provided as voltage regulator usefulness, and the voltage difference scalable is used the body both end voltage between its drain-source utmost point;
A controller, grid voltage for described first field-effect transistor of control, and can detect the change in voltage of described application body and produce negative feedback voltage to the grid of described first field-effect transistor, make that voltage difference produces bucking voltage automatically between its drain-source utmost point;
A current controller is a set point for the strangulation drive current; And
A variable voltage source, for the power supply input of accepting external voltage, but the direct voltage of output modulation is to described dc supply input.
Next the invention provides a kind of drive system, drives one and uses body generation stabilized driving electric current, and it comprises:
A dc supply input is for input direct voltage;
Use output for one, use height current potential place for connecting;
Use input for one, use body electronegative potential place for connecting;
One first field-effect transistor is provided as voltage regulator and uses;
One first operational amplifier can be detected the change in voltage of described application body and produces negative feedback voltage to the grid of described first field-effect transistor, makes that voltage difference produces bucking voltage automatically between its drain-source utmost point; And
A current controller is a set point for the strangulation drive current, is using between body and the earth terminal with the input drive current, and described current controller comprises that a reference current source and one are according to 1: the N ratio amplifies the current mirror of described reference current Iref;
Described reference current source is for output stable reference electric current I ref;
Describedly comply with 1: the N ratio amplifies the current mirror of described reference current Iref, is reference current Iref*N for the strangulation input current.
For can make the present invention above-mentioned within appearance, purpose, advantage and other feature can become apparent, below cooperate graphicly to describe the present invention in detail with preferred embodiment.
Description of drawings
Figure 1A is drive system embodiment one circuit diagram of the present invention;
Figure 1B is variable voltage source embodiment one circuit diagram of the present invention;
Fig. 2 A is that tradition is decided voltage driven system;
Fig. 2 B is that tradition is decided current drive system;
Fig. 3 is current controller embodiment one circuit diagram of the present invention;
Fig. 4 A is the corresponding system temperature variation diagram of the drive current of overtemperature protection operation of the present invention;
Fig. 4 B is a drive current variations figure of overcurrent protection operation of the present invention;
Fig. 4 C is two drive current variations figure of overcurrent protection operation of the present invention;
Fig. 5 is the program description figure of control type driver of the present invention;
Fig. 6 A is a conventional current mirror circuit schematic diagram;
Fig. 6 B is an improvement after-current mirror circuit schematic diagram of the present invention.
Description of reference numerals: 110-variable voltage source; The 120-light-emitting diode group; The 140-current controller; 160-control interface (control interface); The VDD-external input voltage; The voltage of Vo-direct voltage source input; 131-first field-effect transistor (1stFET); Electric capacity before C-first field-effect transistor drain electrode (drain) or source electrode (source) ground connection; The driving voltage of VLED-light-emitting diode group; The drive current of ILED-light-emitting diode group; 132-first operational amplifier (1stOpAmp); The positive input terminal of Vset1-first operational amplifier (positive input) voltage; 111-DC-DC transducer (DC-DC converter); 112-voltage selecting circuit; 113-voltage is chosen signal; 114-feedback voltage (feed back voltage); Resistance 1 in the Ra-selecting circuit; Resistance 2 in the Rb-selecting circuit; Resistance 3 in the Rc-selecting circuit; Resistance 4 in the Rd-selecting circuit; 210,220-LED drive; R-decides the resistance of voltage driven system; Vset-decides the setting voltage of voltage driven system; Rset-decides the resistance of current drive system; 141-the 3rd operational amplifier (3rdOp Amp); 142-second field-effect transistor (2ndFET); The positive carrier channel current of 143-mirror (p channelcurrent mirror); 144-second operational amplifier (2ndOpAmp); 145-is according to 1: the N ratio amplifies the current mirror (current mirror) of reference current; 146-reference current input; 147-reference current source (referencecurrent source); The positive input terminal voltage of Vset3-the 3rd operational amplifier; The setting resistance of Rset3-reference current source; The Iset3-reference current source is set the circulating current of resistance; The reference current of Iref-reference current source output; The negative input end voltage of Vset2-second operational amplifier; The positive input terminal voltage of Vset1-first operational amplifier; The Tsys-system temperature; The start-up temperature of T1-overtemperature protection (over-temperature protection); The releasing temperature of T2-overtemperature protection; Iapp-uses the drive current of body (application); The drive current higher limit of Imax-overcurrent protection; 500-control type driver; 501-uses output; 502-uses input; The 510-dc supply input; 520-uses body (application); 530-controller (controller); 534-grid voltage switch; 532-negative feedback (negative feedback) controller; The 551-voltage controller; The 552-temperature sensor; The 553-current monitor; Vapp1-uses the voltage of output; Vapp2-uses the voltage of input; 611,612-conventional current mirror.
Embodiment
Below in conjunction with accompanying drawing, be described in more detail with other technical characterictic and advantage the present invention is above-mentioned.
The present invention is that a kind of control type driver (control lable driver) 500 produces stabilized driving electric current I app for driving between the high cold end (Vapp1 50 1and Vapp2502) of using body (application) 520, mainly comprise: a dc supply input 510, for input direct voltage Vo; One first field-effect transistor (1stfieldeffecttransistor, FET) 131, being provided as voltage regulator (voltage adjustor) uses, the voltage difference scalable is used body both end voltage (Vapp1-Vapp2) between its drain-source utmost point (drain to source), with voltage requirements (voltage desire) that relieves described application body and the effect that reaches stabilized driving electric current I app; A controller (controller) 530 is for grid (gate) voltage of described first field-effect transistor of control; And: a current controller (current controller) 140 is a set point for strangulation (clamp) drive current.Wherein, described controller also can be detected the change in voltage 532 of described application body to produce the grid of negative feedback (feedback) voltage to described first field-effect transistor, make that voltage difference produces bucking voltage automatically between its drain-source utmost point (drain to source), with the voltage requirements (voltage desire) that relieves described application body.Through negative feedback loop thus, control type driver of the present invention can be kept the driving current value of high stability spontaneously, even under the objective and subjective condition dangerously steep, still can automatically adjust the driving current value that suitable driving voltage sets with cooperation in the face of significantly voltage source fluctuation, application body equivalent resistance (effective resistor) variation or the like.
In addition, the control type driver of the present invention variable voltage source (adjustable-voltagesource) 110 of also can arranging in pairs or groups, for the power supply input of accepting external voltage VDD, but the direct voltage Vo of output modulation is to described dc supply input; Add a control interface (control interface) 160, make control type driver of the present invention can accept the value that direct voltage Vo is directly controlled in user's instruction (user command), so, the scope that driving voltage can be regulated is elasticity more again, uses the scope that physical efficiency uses and also promote widely.
Simultaneously; in order to make control type driver of the present invention more stably operate (operation); can be on the grid voltage of described first field-effect transistor be online 534 or described current controller on install overtemperature protection (over-temperature protection) and overcurrent protection (over-current protection) so that the overheated upper limit of in time blocking drive current during with the overcurrent phenomenon or setting electric current takes place.And the temperature sensor that cooperates with protective device (temperature sensor) 552 also can be included in the control type driver of the present invention with current monitor (current monitor) 553.
The present invention is that a kind of drive system (driving system) drives application body (application) generation stabilized driving electric current, and described drive system mainly comprises following six parts: a dc supply input 510, for input direct voltage Vo; Using output (output for application) 501 for one, is Vapp1 for connecting application height current potential place and described place voltage; Using input (input for application) 502 for one, is Vapp2 for connecting application body electronegative potential place and described place voltage; One first field-effect transistor (1stfieldeffecttransistor, FET) 131, be provided as voltage regulator (voltage adjustor) and use; One first operational amplifier (1stoperationamplifier, OpAmp) 132, can detect the change in voltage of described application body and produce the grid of negative feedback voltage to described first field-effect transistor, make that voltage difference produces bucking voltage automatically between its drain-source utmost point (drain to source), reach the effect of stabilized driving electric current I app with the voltage requirements (voltage desire) that relieves described application body. And a current controller (current controller) 140, be set point for strangulation (clamp) drive current.
For reaching the purpose of described current controller, described current controller can be put and use between body and the earth terminal to import drive current (the application body of giving an example among the figure is a light-emitting diode group 120) as shown in Figure 3, wherein and comprise: a reference current source 147, for output stable reference electric current (reference current) Iref; And one according to 1: the N ratio amplifies the current mirror (current mirror) 145 of described reference current Iref, is reference current Iref*N for the strangulation input current.In order accurately to grasp described 1: the N magnification ratio makes the control of drive current more accurate, shown in Fig. 6 B, described current mirror also comprises one second operational amplifier (2ndOpAmp) 144, common gate (common-gate) the common-battery position of the output common-battery position of its positive input terminal (positive input) and described reference current source and its output (output) and described current mirror, and make the positive input terminal voltage Vset1 equipotential (Vset2=Vset1) of its negative input end (negative input) voltage Vset2 and described first operational amplifier 132, except definitely grasping the effect of strangulation, simultaneously, avoid a large amount of system spaces that as traditional current mirror design (seeing Fig. 6 A), account for again.Described reference current source wherein also comprises in addition: one the 3rd operational amplifier (3rdOpAmp) 141, its positive input terminal are imported an energy gap reference voltage (energy gapreference voltage) and its negative input end and output thereof are connected to form the negative feedback circuit; One second field-effect transistor (2ndFET) 142, its grid source electrode is positioned on the negative feedback circuit of described the 3rd operational amplifier, its grid is connected and its source electrode is connected with the negative input end of described the 3rd operational amplifier with the output of described the 3rd operational amplifier, supplying the voltage of the negative input end of described the 3rd operational amplifier of strangulation is fixed value, and is subjected to the voltage control of the positive input terminal of described the 3rd operational amplifier; A resistance R set3 is between the negative input end and earth terminal of described the 3rd operational amplifier, for producing an electric current I set3 by described second field-effect transistor; And a positive carrier channel current mirror (p channel current mirror) 143, supply the electric current I set3 of acceptance, and export reference current Iref at the other end of described positive carrier channel current mirror by described second field-effect transistor.
For make use voltage requirements (voltage desire) that body produces can with the time relieved, the source electrode of described first field-effect transistor (source) can be connected with described application output, and its drain electrode (drain) is connected with described dc voltage input end, for the voltage difference of regulating between direct voltage Vo and described application output Vapp1, and described first operational amplifier (1stoperationamplifier, OpAmp) negative input end can be imported described application input terminal voltage Vapp2, and at the grid (gate) of its output output negative feedback voltage (negative feedback voltage) to described first field-effect transistor; The drain electrode of described first field-effect transistor is connected with described application input, and its source electrode is connected with the negative input end of described first operational amplifier, voltage difference for the negative input end of regulating described application input Vapp2 and described first operational amplifier, and at the grid of the output of described first operational amplifier output negative feedback voltage (negative feedback voltage) to described first field-effect transistor, all can make described first field-effect transistor energy its drain-source utmost point of automatic synchronization (drain to source) voltage difference, for relieving voltage requirements to reach the effect of stabilized driving electric current.In circuit arrangement, also need an electric capacity to be connected back ground connection, for the voltage of regulating its source electrode or drain electrode with the source electrode (source) or the drain electrode (drain) of described first field-effect transistor.
Often occur in superheating phenomenon and the overcurrent phenomenon that high wattage is used body in order to solve, but system's unit temp transducer (thermal sensor), for monitoring system temperature T sys, make system overheat (be blocked drive current during Tsys＞T1), and hang down in safe temperature at system temperature and (to start drive current (shown in Fig. 4 A arrow) once again behind the Tsys＜T2); System also can install drive current monitor (current monitor) and directly block drive current (as Fig. 4 B) or holding current (as Fig. 4 C) when the overcurrent phenomenon takes place, for directly preventing in drive system using the serious damage of body.In drive system of the present invention; can be directly on the grid voltage of described first field-effect transistor is online 534 or the output of described second operational amplifier 144 on installing overtemperature protection and overcurrent protection, give overtemperature protection and overcurrent protective device and do not need to be provided with separately one group of loop.
The drive system of the present invention variable voltage source (adjustable-voltage source) 110 of also can arranging in pairs or groups, it has comprised that an external power source input is for the power supply input of accepting external voltage VDD, shown in Figure 1B,, carry out output dc voltage Vo after transformation and the rectification for external input voltage VDD again by a DC-DC transducer (DC-DC converter) 111 or pressurizer (voltage regulator) or exchange and change direct current transducer (AC-DC converter); Digital control (digital control) circuit that cooperates a voltage selecting circuit 112 or an analog switch (analog switch) again, accept the voltage of outside input and choose signal 113, for choosing (switch) suitable voltage circuit (circuit), and, make described output voltage V o to choose signal changing by described voltage according to selected voltage circuit feedback voltage (feedback voltage) 114 to external input voltage VDD and the circuit between output voltage V o.Choose the more convenient use of voltage for making described variable voltage source, can cooperate a control interface (control interface) 160 to be responsible for accepting user's instruction (user command) again and handle users' instruction, export the described outside voltage of importing and choose signal to variable voltage source and change voltage circuit via a voltage controller 551.In addition, direct current transducer is changeed in described DC-DC transducer 111 or pressurizer or interchange, can have low pressure reduction voltage stabilizing function (low drop-out), for stablizing the voltage dissipation phenomenon that low input causes; Wherein also can comprise one or more charge pumps (charge pump), for carrying out voltage up-down.So, the scope that driving voltage can be regulated is elasticity more again, uses the scope that physical efficiency uses and also promote widely.
To sum up, according to the above-mentioned graphic and explanation that discloses, the present invention can reach its intended purposes, and a kind of high stability control type driver and drive system are provided, can be for the utilization on the industry.
The above only is preferred embodiment of the present invention, only is illustrative for the purpose of the present invention, and nonrestrictive.Those skilled in the art is understood, and can carry out many changes to it in the spirit and scope that claim of the present invention limited, revise, even equivalence, but all will fall within the scope of protection of the present invention.
Claims (40)
1. a LED drive produces the stabilized driving electric current for driving between the high cold end of using body, it is characterized in that: comprising:
A dc supply input is for input direct voltage;
One first field-effect transistor is provided as voltage regulator usefulness, and the voltage difference scalable is used the body both end voltage between its drain-source utmost point;
A controller, grid voltage for described first field-effect transistor of control, and can detect the change in voltage of described application body and produce negative feedback voltage to the grid of described first field-effect transistor, make that voltage difference produces bucking voltage automatically between its drain-source utmost point;
A current controller is a set point for the strangulation drive current; And
A variable voltage source, for the power supply input of accepting external voltage, but the direct voltage of output modulation is to described dc supply input.
2. LED drive according to claim 1 is characterized in that: also comprise: a control interface, handle for accepting user's instruction and output signal to described controller.
3. LED drive according to claim 1 is characterized in that: also comprise: a kind of overtemperature protection measure, when system temperature generation superheating phenomenon, control the grid voltage of described first field-effect transistor to block drive current.
4. LED drive according to claim 1 is characterized in that: also comprise: a kind of overcurrent protection measure, when drive current generation overcurrent phenomenon, control the grid voltage of described first field-effect transistor to block drive current.
5. LED drive according to claim 1 is characterized in that: also comprise: a kind of overtemperature protection measure, and when system temperature generation superheating phenomenon, control described current controller and block drive current.
6. LED drive according to claim 1 is characterized in that: also comprise: a kind of overcurrent protection measure, and when drive current generation overcurrent phenomenon, control described current controller and block drive current.
7. LED drive according to claim 1 is characterized in that: also comprise: a kind of overcurrent protection measure makes described current controller controlling and driving electric current must not exceed a higher limit when drive current generation overcurrent phenomenon.
8. LED drive according to claim 1 is characterized in that: also comprise: a voltage controller, and for the value that changes described variable voltage source output dc voltage.
9. LED drive according to claim 1 is characterized in that: also comprise: a temperature sensor is carried out overtemperature protection when system temperature generation superheating phenomenon.
10. LED drive according to claim 1 is characterized in that: also comprise: a current monitor, and for the variation of monitoring driving electric current, and when taking place, the overcurrent phenomenon carries out overcurrent protection.
11. LED drive according to claim 1 is characterized in that: also comprise: an electric capacity is connected back ground connection with the source electrode of described first field-effect transistor, for the voltage of regulating its source electrode.
12. LED drive according to claim 1 is characterized in that: also comprise: an electric capacity is connected back ground connection with the drain electrode of described first field-effect transistor, for the voltage of regulating its drain electrode.
13. a drive system drives one and uses body generation stabilized driving electric current, it is characterized in that: comprising:
A dc supply input is for input direct voltage;
Use output for one, use height current potential place for connecting;
Use input for one, use body electronegative potential place for connecting;
One first field-effect transistor is provided as voltage regulator and uses;
One first operational amplifier can be detected the change in voltage of described application body and produces negative feedback voltage to the grid of described first field-effect transistor, makes that voltage difference produces bucking voltage automatically between its drain-source utmost point; And
A current controller is a set point for the strangulation drive current, is using between body and the earth terminal with the input drive current, and described current controller comprises that a reference current source and one are according to 1: the N ratio amplifies the current mirror of described reference current Iref;
Described reference current source is for output stable reference electric current I ref;
Describedly comply with 1: the N ratio amplifies the current mirror of described reference current Iref, is reference current Iref*N for the strangulation input current.
14. drive system according to claim 13, it is characterized in that: also comprise: one second operational amplifier, the output common-battery position of its positive input terminal and described reference current source and the common gate common-battery position of its output and described current mirror, and make the positive input terminal voltage equipotential of its negative input end voltage and described first operational amplifier, for accurately grasping described 1: the N magnification ratio makes the control of drive current more accurate.
15. drive system according to claim 13 is characterized in that: described reference current source should comprise:
One the 3rd operational amplifier, its positive input terminal are imported an energy gap reference voltage and its negative input end and output thereof are connected to form the negative feedback circuit;
One second field-effect transistor, its grid source electrode is positioned on the negative feedback circuit of described the 3rd operational amplifier, its grid is connected and its source electrode is connected with the negative input end of described the 3rd operational amplifier with the output of described the 3rd operational amplifier, supplying the voltage of the negative input end of described the 3rd operational amplifier of strangulation is fixed value, and is subjected to the voltage control of the positive input terminal of described the 3rd operational amplifier;
A resistance is between the negative input end and earth terminal of described the 3rd operational amplifier, for producing an electric current by described second field-effect transistor; And
A positive carrier channel current mirror supplies the electric current of acceptance by described second field-effect transistor, and exports reference current at the other end of described positive carrier channel current mirror.
16. drive system according to claim 13 is characterized in that: described first field-effect transistor is a metal oxide semiconductcor field effect transistor.
17. drive system according to claim 13 is characterized in that: described second field-effect transistor is a metal oxide semiconductcor field effect transistor.
18. drive system according to claim 13 is characterized in that: also comprise: a variable voltage source, for the power supply input of accepting external voltage, but the direct voltage of output modulation is to described dc supply input.
19. drive system according to claim 13 is characterized in that: also comprise: a control interface, for accepting the every setting of user's instruction with the change drive system.
20. drive system according to claim 13, it is characterized in that: the source electrode of described first field-effect transistor is to be connected with described application output, and its drain electrode is connected with described dc voltage input end, for the voltage difference of regulating between direct voltage and described application output; And the negative input end of described first operational amplifier is the described application input terminal voltage of input, and at the grid of its output output negative feedback voltage to described first field-effect transistor, and make described first its drain-source voltage of field-effect transistor automatic synchronization poor.
21. drive system according to claim 13, it is characterized in that: the drain electrode of described first field-effect transistor is to be connected with described application input, and its source electrode is connected with the negative input end of described first operational amplifier, for the voltage difference of the negative input end of regulating described application input and described first operational amplifier; And at the grid of the output of described first operational amplifier output negative feedback voltage to described first field-effect transistor, and make described first its drain-source voltage of field-effect transistor automatic synchronization poor.
22. drive system according to claim 13 is characterized in that: also comprise: an electric capacity is connected back ground connection with the source electrode of described first field-effect transistor, for the voltage of regulating its source electrode.
23. drive system according to claim 13 is characterized in that: also comprise: an electric capacity is connected back ground connection with the drain electrode of described first field-effect transistor, for the voltage of regulating its drain electrode.
24. drive system according to claim 13 is characterized in that: also comprise: a kind of overtemperature protection, when system temperature generation superheating phenomenon, control the grid voltage of described first field-effect transistor to block drive current.
25. drive system according to claim 13 is characterized in that: also comprise: a kind of overcurrent protection, when drive current generation overcurrent phenomenon, control the grid voltage of described first field-effect transistor to block drive current.
26. drive system according to claim 13 is characterized in that: also comprise: a kind of overtemperature protection, control described 1 when system temperature generation superheating phenomenon: the common gate voltage of N ratio current mirror is to block drive current.
37. drive system according to claim 13 is characterized in that: also comprise: a kind of overcurrent protection measure, control described 1 when drive current generation overcurrent phenomenon: the common gate voltage of N ratio current mirror is to block drive current.
28. drive system according to claim 13 is characterized in that: also comprise: a kind of overcurrent protection measure, control described 1 when drive current generation overcurrent phenomenon: N ratio current mirror makes drive current must not exceed a higher limit.
29. drive system according to claim 18 is characterized in that: also comprise: a voltage controller, for the value of the described variable voltage source change of control output dc voltage.
30. drive system according to claim 13; it is characterized in that: also comprise: a temperature sensor is for the detecting system variation of temperature; when system overheat, carry out overtemperature protection, and hang down after safe temperature normal operation drive current once again at system temperature.
31. drive system according to claim 13 is characterized in that: also comprise: a current monitor, for the variation of monitoring driving electric current, and when taking place, the overcurrent phenomenon carries out overcurrent protection.
32. drive system according to claim 18 is characterized in that: described variable voltage source comprises a pressurizer, carries out output dc voltage after transformation and the rectification for external input voltage.
33. drive system according to claim 18 is characterized in that: described variable voltage source comprises the direct current transducer that always circulates, and carries out output dc voltage after transformation and the rectification for external input voltage.
34. drive system according to claim 18 is characterized in that: described variable voltage source comprises that one exchange to change direct current transducer, carries out output dc voltage after transformation and the rectification for external input voltage.
35. drive system according to claim 18 is characterized in that: described variable voltage source also comprises one or most charge pump, for carrying out the lifting of voltage.
36. drive system according to claim 18, it is characterized in that: described variable voltage source also comprises a voltage selecting circuit, for accepting voltage signal and choosing suitable voltage circuit, make its feedback voltage to circuit between external input voltage and the output dc voltage, and change the magnitude of voltage of described variable voltage source output.
37. drive system according to claim 18, it is characterized in that: described variable voltage source also comprises the digital control circuit of an analog switch, supply to accept the instruction of voltage change to choose suitable voltage circuit, and make its feedback voltage to circuit between external input voltage and the output dc voltage, and change the magnitude of voltage of described variable voltage source output.
38. drive system according to claim 19 is characterized in that: described voltage controller can be regulated signal is controlled described application body for the user switch and flicker form with pulse bandwidth.
39. drive system according to claim 13 is characterized in that: described drive system is for driving LED for illumination.
40. drive system according to claim 13 is characterized in that: described drive system is for driving the backlight light-emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200610170231A CN100579325C (en) | 2006-12-21 | 2006-12-21 | Light emitting diode driver as well as driving system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200610170231A CN100579325C (en) | 2006-12-21 | 2006-12-21 | Light emitting diode driver as well as driving system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101207953A CN101207953A (en) | 2008-06-25 |
| CN100579325C true CN100579325C (en) | 2010-01-06 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN200610170231A Expired - Fee Related CN100579325C (en) | 2006-12-21 | 2006-12-21 | Light emitting diode driver as well as driving system |
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Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101646281A (en) * | 2008-08-08 | 2010-02-10 | 立锜科技股份有限公司 | Device and method for driving LED |
| CN101672431B (en) * | 2008-09-08 | 2012-05-23 | 索玉昇 | Group control type illumination control system |
| CN101730329B (en) * | 2008-10-10 | 2013-08-21 | 华映视讯（吴江）有限公司 | Back light module control system and control method thereof |
| US8503145B2 (en) * | 2010-04-14 | 2013-08-06 | Vektrek Electronic Systems, Inc. | Fault protected current source for lighting element testing |
| CN102235601B (en) * | 2010-04-29 | 2013-06-12 | 安恩国际公司 | Dual-end current controller and relevant light emitting diode lighting device |
| JP5572454B2 (en) * | 2010-06-29 | 2014-08-13 | 日立アプライアンス株式会社 | LED lighting device |
| TWI419121B (en) | 2010-09-23 | 2013-12-11 | Novatek Microelectronics Corp | Integrated backlight driving chip and led backlight device |
| CN102446491A (en) * | 2010-10-08 | 2012-05-09 | 联咏科技股份有限公司 | Integrated backlight driving chip and light emitting diode backlight device |
| CN103701086B (en) * | 2012-09-27 | 2016-03-30 | 英业达科技有限公司 | Circuit protection device |
| CN104102263B (en) * | 2014-05-30 | 2015-11-25 | 北京航天自动控制研究所 | A kind of constant-current source circuit of belt current monitoring |
| CN104143818B (en) * | 2014-08-19 | 2017-07-21 | 圣邦微电子（北京）股份有限公司 | Prevent the device that current-limiting circuit is excessively adjusted |
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2006
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| Publication number | Publication date |
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| CN101207953A (en) | 2008-06-25 |
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