CN104363674A - Led light source driving circuit - Google Patents

Led light source driving circuit Download PDF

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Publication number
CN104363674A
CN104363674A CN201410528687.6A CN201410528687A CN104363674A CN 104363674 A CN104363674 A CN 104363674A CN 201410528687 A CN201410528687 A CN 201410528687A CN 104363674 A CN104363674 A CN 104363674A
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Prior art keywords
drive circuit
light source
led light
resistance
circuit
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CN201410528687.6A
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CN104363674B (en
Inventor
李壮
韦佼宜
韩大海
张民
展祯
唐雄燕
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BEIJING GUANGXIA NETWORK TECHNOLOGY Co Ltd
Beijing University of Posts and Telecommunications
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BEIJING GUANGXIA NETWORK TECHNOLOGY Co Ltd
Beijing University of Posts and Telecommunications
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Abstract

The invention provides an LED light source driving circuit. The LED light source driving circuit comprises an operational amplifier circuit, a distortionless driving circuit, a predistortion driving circuit and a direct-current bias circuit, wherein the operational amplifier circuit is used for amplifying original voltage signals and outputting the amplified voltage signals to the distortionless driving circuit and the predistortion driving circuit respectively, the distortionless driving circuit outputs alternating-current signals to the direct-current bias circuit according to the received amplified voltage signals, the predistortion driving circuit outputs the alternating-current signals of the high-frequency part to the direct-current bias circuit according to the received amplified voltage signals. The signals outputted by the driving circuits are superposed to be inputted into the direct-current bias circuit, and are combined with the inputted direct-current voltage to output to an LED light source. The LED light source driving circuit solves the problem that the LED light source is poor in response performance to the high-frequency signals and communication speed of the LED light source is improved.

Description

LED light source drive circuit
Technical field
The present invention relates to optical communication field, particularly relate to a kind of LED light source drive circuit.
Background technology
Light-emitting diode (Light Emitting Diode is called for short LED), as new type light source, owing to having energy-saving and environmental protection, efficiently feature, has been widely used in the various aspects such as illumination, display and signal designation.At present, the visible light communication technology utilizing LED light source to realize has without the need to radio-frequency spectrum certification, there is not the characteristics such as electromagnetic interference, confidentiality be good and radiationless, a lot of special scenes such as medical treatment, space flight can be applied to, distribution of light sources also makes it in the application of navigation system, obtain very high accuracy widely, a series of advantage also becomes the important supplement technology of the WiFi communication technology in current main-stream radio communication, the market prospects wide based on LED light source and technical continuous maturation thereof, make it become possibility in the application of the illumination communications field.
The blue white LED light source of single-chip is one of white LED light source of main flow the most in the market, is also one of light source of mainly studying of vast visible communication technical research institute.But, because its principle emitted white light is for adopting fluorescent material switch technology, make the switching rate of LED light by force for high-frequency signal limited, cause blue white LED light source not good to the response performance of high-frequency signal, it is signal within 3MHz that normal conditions are merely able to response frequency preferably, and this becomes the subject matter limiting its communication speed and improve.
Summary of the invention
For defect of the prior art, the invention provides a kind of LED light source drive circuit, solve the problem that LED light source is not good to the response performance of high-frequency signal, improve the traffic rate of LED light source simultaneously.
The invention provides a kind of LED light source drive circuit, comprising: discharge circuit, undistorted drive circuit, predistortion drive circuit and DC bias circuit;
Described discharge circuit for amplifying raw voltage signals, and exports the voltage signal after amplifying to described undistorted drive circuit and described predistortion drive circuit respectively;
Described undistorted drive circuit is according to the voltage signal after the amplification received, and output AC current signal is to described DC bias circuit;
Described predistortion drive circuit, according to the voltage signal after the amplification received, exports the ac current signal of HFS to described DC bias circuit;
Described DC bias circuit receives and the ac current signal of the HFS exported with described predistortion drive circuit by the ac current signal that described undistorted drive circuit exports superposes, and is combined, exports LED light source to the direct voltage of input.
Alternatively, described discharge circuit comprises: amplifier chip, the first resistance and the second resistance;
The first end connecting signal source of described first resistance, the second end of described first resistance connects the inverting input of described amplifier chip; The first end of described second resistance is connected between described first resistance and described amplifier chip inverting input, and the second end of described second resistance connects the output of described amplifier chip; The output of described amplifier chip connects described undistorted drive circuit and described predistortion drive circuit respectively.
Alternatively, the multiplication factor of described amplifier chip is determined by the opposite number of described second resistance and described first resistance ratio.
Alternatively, described undistorted drive circuit comprises: the first electric capacity, the first buffer chip, the 3rd resistance;
The first end of described first electric capacity connects the output of described amplifier chip, and the second end of described first electric capacity connects the input of described first buffer chip; The first end of described 3rd resistance connects the output of described first buffer chip, and the second end of described 3rd resistance connects described DC bias circuit.
Alternatively, described first buffer chip is used for described voltage signal to be converted to current signal.
Alternatively, described predistortion drive circuit comprises: the second electric capacity, the second buffer chip, for improving the high-pass filtering circuit of signal high fdrequency component ratio;
The first end of described second electric capacity connects the output of described amplifier chip, and the second end of described second electric capacity connects the input of described second buffer chip; The first end of described high-pass filtering circuit connects the output of described second buffer chip, and the second end of described high-pass filtering circuit connects described DC bias circuit.
Alternatively, described high-pass filtering circuit is made up of the 3rd electric capacity, the 4th electric capacity, the 4th resistance and the 5th resistant series.
Alternatively, described DC bias circuit comprises: the 5th electric capacity and the first inductance;
The first end of described 5th electric capacity connects described undistorted drive circuit and described predistortion drive circuit respectively, and the second end of described 5th electric capacity connects described first inductance; Second end of shown first inductance connects LED light source.
As shown from the above technical solution, LED light source drive circuit of the present invention, comprising: discharge circuit, undistorted drive circuit, predistortion drive circuit and DC bias circuit; Described discharge circuit for amplifying raw voltage signals, and exports the voltage signal after amplifying to described undistorted drive circuit and described predistortion drive circuit respectively; Described undistorted drive circuit is according to the voltage signal after the amplification received, and output AC current signal is to described DC bias circuit; Described predistortion drive circuit, according to the voltage signal after the amplification received, exports the ac current signal of HFS to described DC bias circuit; Described DC bias circuit receives and is superposed by the ac current signal of described ac current signal with described HFS, is combined, exports LED light source to the direct voltage of input.Solve the problem that LED light source is not good to the response performance of high-frequency signal, improve the traffic rate of LED light source simultaneously.
Accompanying drawing explanation
The structured flowchart of the LED light source drive circuit that Fig. 1 provides for one embodiment of the invention;
The circuit diagram of the LED light source drive circuit that Fig. 2 provides for one embodiment of the invention;
The frequency response chart of the predistortion drive circuit that Fig. 3 provides for one embodiment of the invention;
The frequency response chart of the two-way drive circuit superposition that Fig. 4 provides for one embodiment of the invention.
Embodiment
Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples for illustration of the present invention, but are not used for limiting the scope of the invention.
Fig. 1 shows the structured flowchart of the LED light source drive circuit that one embodiment of the invention provides, and as shown in Figure 1, comprises discharge circuit 11, undistorted drive circuit 12, predistortion drive circuit 13 and DC bias circuit 14;
Described discharge circuit 11 for amplifying raw voltage signals, and exports the voltage signal after amplifying to described undistorted drive circuit 12 and described predistortion drive circuit 13 respectively;
Described undistorted drive circuit 12 is according to the voltage signal after the amplification received, and output AC current signal is to described DC bias circuit 14;
Described predistortion drive circuit 13, according to the voltage signal after the amplification received, exports the ac current signal of HFS to described DC bias circuit 14;
Described DC bias circuit 14 receives and the ac current signal of the HFS exported with described predistortion drive circuit 13 by the ac current signal that described undistorted drive circuit 12 exports superposes, and is combined, exports LED light source to the direct voltage of input.
The LED light source drive circuit of the present embodiment, comprising: discharge circuit, undistorted drive circuit, predistortion drive circuit and DC bias circuit; Described discharge circuit for amplifying raw voltage signals, and exports the voltage signal after amplifying to described undistorted drive circuit and described predistortion drive circuit respectively; Described undistorted drive circuit is according to the voltage signal after the amplification received, and output AC current signal is to described DC bias circuit; Described predistortion drive circuit, according to the voltage signal after the amplification received, exports the ac current signal of HFS to described DC bias circuit; Described DC bias circuit receives and is superposed by the ac current signal of described ac current signal with described HFS, is combined, exports LED light source to the direct voltage of input.Solve the problem that LED light source is not good to the response performance of high-frequency signal, improve the traffic rate of LED light source simultaneously.
Be described with annexation: Fig. 2 shows the circuit diagram of the LED light source drive circuit that one embodiment of the invention provides, as shown in Figure 2;
Described discharge circuit 11 comprises: amplifier chip, the first resistance R 1, the second resistance R 2;
Described first resistance R 1first end connecting signal source, described first resistance R 1the second end connect the inverting input of described amplifier chip; Described second resistance R 2first end be connected between described first resistance and described amplifier chip inverting input, described second resistance R 2the second end connect the output of described amplifier chip; The output of described amplifier chip connects described undistorted drive circuit 12 and described predistortion drive circuit 13 respectively.
Described undistorted drive circuit 12 comprises: the first electric capacity C 1, the first buffer chip BUFFER-1 and the 3rd resistance R 3;
Described first electric capacity C 1first end connect the output of described amplifier chip, described first electric capacity C 1the second end connect the input of described first buffer chip BUFFER-1; Described 3rd resistance R 3first end connect the output of described first buffer chip BUFFER-1, described 3rd resistance R 3the second end connect described DC bias circuit 14.
Described predistortion drive circuit 13 comprises: the second electric capacity C 2, the second buffer chip BUFFER-2, for improving the high-pass filtering circuit of signal high fdrequency component ratio;
Alternatively, described high-pass filtering circuit is by the 3rd electric capacity C 3, the 4th electric capacity C 4, the 4th resistance R 4with the 5th resistance R 5be composed in series.
Described second electric capacity C 2first end connect the output of described amplifier chip, described second electric capacity C 2the second end connect the input of described second buffer chip BUFFER-2; The first end of described high-pass filtering circuit connects the output of described second buffer chip BUFFER-2, and the second end of described high-pass filtering circuit connects described DC bias circuit 14.
Described DC bias circuit 14 comprises: the 5th electric capacity C 5with the first inductance L 1;
Described 5th electric capacity C 5first end connect respectively described undistorted drive circuit 12 and described predistortion drive circuit 13, described 5th electric capacity C 5second end connect described first inductance L 1; Shown first inductance L 1second end connect LED light source.
Be described with signal stream:
Described discharge circuit 11 receives the raw voltage signals from signal source, and described raw voltage signals is by the first resistance R 1export the inverting input of described amplifier chip to, according to described second resistance R 2with described first resistance R 1the opposite number of ratio determine concrete multiplication factor, described raw voltage signals is amplified, finally exports the voltage signal after amplifying respectively to described undistorted drive circuit 12 and described predistortion drive circuit 13.
It should be noted that, the effect of described discharge circuit is amplified to by raw voltage signals in the voltage range of suitable whole LED light source drive circuit, described amplifier chip ensures the voltage signal magnitude scope that signal will be adjusted, and ensure adjust the multiplication factor of voltage signal in useful frequency range consistent.
Will be understood that, the concrete multiplication factor of described amplifier chip is by the first resistance R 1and the second resistance R 2jointly determine: described first resistance R 1with the second resistance R 2acting in conjunction regulates modulation depth and the amplitude of voltage signal to be communicated.
Described undistorted drive circuit 12 receives the voltage signal after from the amplification of described discharge circuit 11, and the voltage signal after described amplification is by described first electric capacity C 1remove invalid DC component, the voltage signal retaining the alternating current component of carry information exports the input of described first buffer chip BUFFER-1 to, and the voltage signal received is converted to current signal and exports described DC bias circuit 14 to by described first buffer chip BUFFER-1.
It should be noted that, described undistorted drive circuit remains the integrality of signal of communication, the utilization of described first cache chip BUFFER-1 reaches the effect driving great power LED, and the large voltage signal of input is converted to High-current output in order to drive great power LED.
Will be understood that, described 3rd resistance R3 remains signal intermediate frequency rate component proportion, and has reconciled the amplitude of distortion free signal.
Described predistortion drive circuit 13 receives the voltage signal after from the amplification of described discharge circuit 11, and the voltage signal after described amplification is by described second electric capacity C 2remove invalid DC component, the voltage signal retaining the alternating current component of carry information exports the input of described second buffer chip BUFFER-2 to, the voltage signal received is converted to current signal and exports the HFS that described high-pass filtering circuit retains described current signal to by described second buffer chip BUFFER-2, exports described HFS to described DC bias circuit 14.
It should be noted that described predistortion drive circuit 13 improves the radio-frequency component of signal of communication, the calculating of the high-frequency filter circuit cut-off frequency of described predistortion drive circuit 13 is determined according to cut-off frequency formula and experience.
Visible, it is bad to high frequency response performance in communication process that the design of above-mentioned two-way drive circuit compensate for LED light source, the problem of limiting telecommunication speed.
Fig. 3 shows the frequency response chart of the predistortion drive circuit that one embodiment of the invention provides, the ac current signal of incoming frequency scope in 100kHz ~ 100MHz, known LED light source can obtain good frequency response on gain-3dB based on experience value, observe the frequency range of gain within-3dB, as shown in Figure 3, when yield value is-3.006dB, frequency values is now 2.55Hz, known when ac current signal is after by above-mentioned predistortion drive circuit, the radio-frequency component of frequency at more than 2.55kHz can be remained preferably, correspondingly, low frequency part decay is larger.
Described DC bias circuit 14 receives and the AC signal of the AC signal of described undistorted drive circuit 12 and the HFS of described predistortion drive circuit 13 is superposed, as the first input signal of described DC bias signal 14, by described first input signal by described 5th electric capacity C 5with described first inductance L 1, and export LED light source to the d. c. voltage signal combination as the second input.
It should be noted that described DC bias circuit 14 ensure that being supplied to the d. c. voltage signal that LED normally works effectively is combined with the AC signal controlling the former power of LED light, and be passed to LED light source.
Fig. 4 shows the frequency response chart of undistorted drive circuit that one embodiment of the invention provides and the superposition of predistortion drive circuit, as shown in Figure 4, Fig. 4 is ac current signal that described undistorted drive circuit exports superposes signal afterwards frequency response with the HFS ac current signal that described predistortion drive circuit exports.In like manner, the ac current signal of incoming frequency scope in 100kHz ~ 100MHz, observe the frequency range of gain within-3dB, as shown in Figure 3, when yield value is-3.082dB, frequency values is now 2.968Hz.Because high-frequency signal is lossy by meeting after LED light source, low frequency signal is little on LED light source impact, therefore, after above-mentioned two-way drive circuit superposition, the accounting of HFS can be made to increase the weight of, and then improve LED light source to high fdrequency component frequency response performance.
The present embodiment carries out improvement LED light source drive circuit for the shortcoming that blue white LED light source response speed is slower, achieve and be increased to 10MHz at blue white light LEDs baseband bandwidth from 3MHz, the method cost adopted is low, be easy to technically realize, and under equal conditions can not reduce the transmitting power of LED light source, under the condition not affecting visible light communication distance, significantly improve the traffic rate of system.
Last it is noted that above each embodiment is only in order to illustrate technical scheme of the present invention, be not intended to limit; Although with reference to foregoing embodiments to invention has been detailed description, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein some or all of technical characteristic; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of the claims in the present invention.

Claims (8)

1. a LED light source drive circuit, is characterized in that, comprising: discharge circuit, undistorted drive circuit, predistortion drive circuit and DC bias circuit;
Described discharge circuit for amplifying raw voltage signals, and exports the voltage signal after amplifying to described undistorted drive circuit and described predistortion drive circuit respectively;
Described undistorted drive circuit is according to the voltage signal after the amplification received, and output AC current signal is to described DC bias circuit;
Described predistortion drive circuit, according to the voltage signal after the amplification received, exports the ac current signal of HFS to described DC bias circuit;
Described DC bias circuit receives and the ac current signal of the HFS exported with described predistortion drive circuit by the ac current signal that described undistorted drive circuit exports superposes, and is combined, exports LED light source to the direct voltage of input.
2. LED light source drive circuit according to claim 1, is characterized in that, described discharge circuit comprises: amplifier chip, the first resistance and the second resistance;
The first end connecting signal source of described first resistance, the second end of described first resistance connects the inverting input of described amplifier chip; The first end of described second resistance is connected between described first resistance and described amplifier chip inverting input, and the second end of described second resistance connects the output of described amplifier chip; The output of described amplifier chip connects described undistorted drive circuit and described predistortion drive circuit respectively.
3. LED light source drive circuit according to claim 2, is characterized in that, the multiplication factor of described amplifier chip is determined by the opposite number of described second resistance and described first resistance ratio.
4. the LED light source drive circuit according to claim 1-3, is characterized in that, described undistorted drive circuit comprises: the first electric capacity, the first buffer chip, the 3rd resistance;
The first end of described first electric capacity connects the output of described amplifier chip, and the second end of described first electric capacity connects the input of described first buffer chip; The first end of described 3rd resistance connects the output of described first buffer chip, and the second end of described 3rd resistance connects described DC bias circuit.
5. LED light source drive circuit according to claim 4, is characterized in that, described first buffer chip is used for described voltage signal to be converted to current signal.
6. the LED light source drive circuit according to claim 1-3, is characterized in that, described predistortion drive circuit comprises: the second electric capacity, the second buffer chip, for improving the high-pass filtering circuit of signal high fdrequency component ratio;
The first end of described second electric capacity connects the output of described amplifier chip, and the second end of described second electric capacity connects the input of described second buffer chip; The first end of described high-pass filtering circuit connects the output of described second buffer chip, and the second end of described high-pass filtering circuit connects described DC bias circuit.
7. LED light source drive circuit according to claim 6, is characterized in that, described high-pass filtering circuit is made up of the 3rd electric capacity, the 4th electric capacity, the 4th resistance and the 5th resistant series.
8. LED light source drive circuit according to claim 1, is characterized in that, described DC bias circuit comprises: the 5th electric capacity and the first inductance;
The first end of described 5th electric capacity connects described undistorted drive circuit and described predistortion drive circuit respectively, and the second end of described 5th electric capacity connects described first inductance; Second end of described first inductance connects LED light source.
CN201410528687.6A 2014-10-09 2014-10-09 LED light source driving circuit Active CN104363674B (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3881250A4 (en) * 2018-11-12 2022-08-24 Newsouth Innovations Pty Ltd A signal combiner
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