TWI489908B - Light emitting diode drive circuit - Google Patents
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Description
本發明是有關於一種驅動電路,特別是指一種發光二極體驅動電路。The invention relates to a driving circuit, in particular to a light emitting diode driving circuit.
近年來,由於發光二極體(Light-Emitting-Diode,簡寫為LED)具有許多適合用於照明的特性且容易調光,使得發光二極體逐漸受到市場的重視,而被廣泛應用於各種照明器具中。In recent years, Light-Emitting-Diode (LED) has many characteristics suitable for illumination and is easy to dim, making the LEDs gradually gain market attention and are widely used in various lightings. In the appliance.
發光二極體為一種使用低電壓直流驅動的元件,一般在通用照明(General Lighting)的應用上,常常會搭配使用降壓式轉換器(Buck Converter)、降升壓式轉換器(Buck-Boost Converter)、或反馳式轉換器(Flyback Converter)作為其驅動電路。A light-emitting diode is a component that uses a low-voltage DC drive. Generally, it is commonly used in general lighting applications. Buck converters and buck-boost converters (Buck-Boost) Converter), or Flyback Converter as its drive circuit.
參閱圖1及圖2,一般降壓式轉換器(如圖1)及降升壓式轉換器(如圖2)中,開關元件11通常設置在高端(High Side),而為了要驅動位於高端的開關元件11,通常會如圖1所示採用高端開關驅動技術(High Side Driver Technique),設置一個高端開關驅動電路12,並以一控制電路13進行控制;或是如圖2所示採用浮動接地(Floating Ground)方式,將控制電路13的參考浮動接地端131電連接至二極體D及繞組L間,以取得一浮動接地電壓。Referring to Figures 1 and 2, in a general buck converter (Fig. 1) and a step-down converter (Fig. 2), the switching element 11 is usually placed at the high side, and is driven at the high end. The switching element 11 usually adopts a high-side switch technique (High Side Driver Technique) as shown in FIG. 1, and a high-side switch driving circuit 12 is provided and controlled by a control circuit 13; or floating as shown in FIG. Grounding In the Ground mode, the reference floating ground terminal 131 of the control circuit 13 is electrically connected between the diode D and the winding L to obtain a floating ground voltage.
然而,無論是採用高端開關驅動技術或是浮動接地方式,都會使高端開關驅動電路12或控制電路13的參考接地電位(浮動接地電壓)與系統的參考接地電位(接地端)為不同電位,如此導致訊號在傳遞過程中沒有統一的參考接地電位可供參考,會造成訊號無法正常被傳送或是偵測。However, whether using high-side switch drive technology or floating grounding method, the reference ground potential (floating ground voltage) of the high-side switch drive circuit 12 or the control circuit 13 and the reference ground potential (ground terminal) of the system are different potentials, As a result, there is no unified reference ground potential for reference during the transmission, which may cause the signal to be not transmitted or detected normally.
參閱圖3及圖4,目前為了解決此一問題,通常會如圖3所示採用一隔離變壓器14,或是如圖4所示採用一光耦合器15來傳遞訊號,以克服參考接地電位不一致對訊號傳遞的影響。Referring to FIG. 3 and FIG. 4, in order to solve this problem, an isolation transformer 14 is usually used as shown in FIG. 3, or an optical coupler 15 is used to transmit signals as shown in FIG. 4 to overcome the inconsistency of the reference ground potential. The impact on signal transmission.
然而隔離變壓器14及光耦合器15皆會使電路體積上升、增加電路成本及設計複雜度,甚至會影響系統之可靠度。However, the isolation transformer 14 and the optical coupler 15 both increase the circuit volume, increase the circuit cost and design complexity, and even affect the reliability of the system.
因此,本發明之目的,即在提供一種可解決上述問題的發光二極體驅動電路。Accordingly, it is an object of the present invention to provide a light emitting diode driving circuit that can solve the above problems.
於是本發明發光二極體驅動電路,適用於驅動複數發光二極體,該發光二極體驅動電路包含:一轉換電路、一控制電路,及一調光訊號位移電路。Therefore, the LED driving circuit of the present invention is suitable for driving a plurality of LEDs, and the LED driving circuit comprises: a conversion circuit, a control circuit, and a dimming signal displacement circuit.
該轉換電路包括:一開關元件、一輸出電容、一電感及一飛輪二極體。The conversion circuit includes: a switching element, an output capacitor, an inductor, and a flywheel diode.
該開關元件具有一接收一電源訊號的第一端、 一第二端,及一接收一控制訊號的控制端,受控制而於導通與截止間切換。The switching element has a first end that receives a power signal, A second end, and a control end receiving a control signal, are controlled to switch between on and off.
該輸出電容具有一提供一輸出電流以驅動該等發光二極體的第一端,及一接地的第二端。The output capacitor has a first end that provides an output current to drive the light emitting diodes and a grounded second end.
該電感及該飛輪二極體串接於該輸出電容的第一端與接地端間,且其連接點電連接於該開關元件的第二端並提供一浮動接地電壓。The inductor and the flywheel diode are connected in series between the first end of the output capacitor and the ground, and the connection point is electrically connected to the second end of the switching element and provides a floating ground voltage.
該控制電路包括:一開關元件控制端、一參考浮動接地端、一調光訊號輸入端、一調光訊號回復模組,及一調光控制模組。The control circuit comprises: a switching element control end, a reference floating ground end, a dimming signal input end, a dimming signal recovery module, and a dimming control module.
該開關元件控制端電連接該開關元件的控制端且提供該控制訊號。The switching element control terminal is electrically connected to the control end of the switching element and provides the control signal.
該參考浮動接地端電連接於該電感與該飛輪二極體之連接點,以接收該浮動接地電壓。The reference floating ground is electrically connected to a connection point of the inductor and the flywheel diode to receive the floating ground voltage.
該調光訊號輸入端用以接收一對應該浮動接地電壓的調光輸入訊號。The dimming signal input terminal is configured to receive a pair of dimming input signals that should have a floating ground voltage.
該調光訊號回復模組電連接該調光訊號輸入端及該參考浮動接地端,接收該調光輸入訊號並對該調光輸入訊號進行訊號回復後輸出。The dimming signal recovery module is electrically connected to the dimming signal input end and the reference floating ground end, and receives the dimming input signal and outputs a signal after the dimming input signal is recovered.
該調光控制模組電連接該調光訊號回復模組及該開關元件控制端,接收訊號回復後的該調光輸入訊號,並根據回復後的該調光輸入訊號調整輸出該控制訊號。The dimming control module is electrically connected to the dimming signal recovery module and the switching element control end, receives the dimming input signal after the signal is recovered, and adjusts and outputs the control signal according to the dimmed input signal after the reply.
該調光訊號位移電路包括:一調光二極體及一調光電容。The dimming signal displacement circuit comprises: a dimming diode and a dimming capacitor.
該調光二極體具有一接收一調光訊號的陽極端,及一輸出該調光輸入訊號的陰極端。The dimming diode has an anode end receiving a dimming signal and a cathode end outputting the dimming input signal.
該調光電容具有一電連接該調光二極體的陰極端的第一端,及一電連接該浮動接地電壓的第二端。The dimming capacitor has a first end electrically connected to the cathode end of the dimming diode, and a second end electrically connected to the floating ground voltage.
本發明之功效在於:藉由使用該調光電容及該調光二極體取代習知技術中的隔離變壓器或光耦合器,不但可以大量節省電路體積及元件、降低電路成本,且在訊號傳遞過程中沒有統一的參考電位可供參考的情況下,仍可正常偵測或傳遞訊號。The effect of the invention is that by using the dimming capacitor and the dimming diode to replace the isolation transformer or the optical coupler in the prior art, the circuit volume and components can be saved, the circuit cost can be saved, and the signal transmission can be realized. In the absence of a uniform reference potential for reference, the signal can still be detected or transmitted normally.
2‧‧‧電源電路2‧‧‧Power circuit
Vac‧‧‧交流電源Vac‧‧‧AC power supply
201‧‧‧交流電源之第一端201‧‧‧The first end of the AC power supply
202‧‧‧交流電源之第二端202‧‧‧The second end of the AC power supply
21‧‧‧橋式整流模組21‧‧‧Bridge rectifier module
D1‧‧‧第一二極體D1‧‧‧First Diode
D2‧‧‧第二二極體D2‧‧‧ second diode
D3‧‧‧第三二極體D3‧‧‧ third diode
D4‧‧‧第四二極體D4‧‧‧ fourth diode
22‧‧‧電磁干擾濾波模組22‧‧‧Electromagnetic interference filter module
Lf‧‧‧電磁干擾濾波電感Lf‧‧‧electromagnetic interference filter inductor
Cf‧‧‧電磁干擾濾波電容Cf‧‧‧Electromagnetic interference filter capacitor
C1‧‧‧濾波電容C1‧‧‧Filter Capacitor
3‧‧‧轉換電路3‧‧‧Transition circuit
Q1‧‧‧開關元件Q1‧‧‧Switching elements
L‧‧‧電感L‧‧‧Inductance
Do‧‧‧飛輪二極體Do‧‧‧Flywheel diode
Co‧‧‧輸出電容Co‧‧‧ output capacitor
Rfb‧‧‧迴授電阻Rfb‧‧‧ feedback resistor
4‧‧‧控制電路4‧‧‧Control circuit
FB‧‧‧迴授端FB‧‧‧reporting end
VSS‧‧‧參考浮動接地端VSS‧‧‧reference floating ground
VDD‧‧‧控制電路之電源端VDD‧‧‧ power supply terminal
DIM‧‧‧調光訊號輸入端DIM‧‧‧ dimming signal input
GATE‧‧‧開關元件控制端GATE‧‧‧ switching element control terminal
COMP‧‧‧相位補償端COMP‧‧‧ phase compensation end
41‧‧‧調光訊號回復模組41‧‧‧ Dimming signal recovery module
411‧‧‧比較器411‧‧‧ comparator
Dsh‧‧‧取樣二極體Dsh‧‧‧Sampling diode
Csh‧‧‧取樣電容Csh‧‧‧Sampling Capacitor
Vf‧‧‧預定電壓源Vf‧‧‧Predetermined voltage source
42‧‧‧調光控制模組42‧‧‧ dimming control module
5‧‧‧調光訊號位移電路5‧‧‧ dimming signal displacement circuit
Cdim‧‧‧調光電容Cdim‧‧‧ dimming capacitor
Ddim‧‧‧調光二極體Ddim‧‧‧ dimming diode
Vref‧‧‧等效電源Vref‧‧‧ equivalent power supply
9‧‧‧發光二極體9‧‧‧Lighting diode
91~93‧‧‧曲線91~93‧‧‧ Curve
本發明之其他的特徵及功效,將於參照圖式的實施方式中清楚地呈現,其中:圖1是一電路示意圖,說明習知一種採用降壓式轉換器及高端開關驅動技術的發光二極體驅動電路;圖2是一電路示意圖,說明習知一種採用降升壓式轉換器及浮動接地方式的發光二極體驅動電路;圖3是一電路示意圖,說明習知一種採用隔離變壓器傳遞訊號的發光二極體驅動電路;圖4是一電路示意圖,說明習知一種採用光耦合器傳遞訊號的發光二極體驅動電路;圖5是本發明發光二極體驅動電路之一第一較佳實施例的電路示意圖;圖6是該第一較佳實施例的一調光訊號回復模組的電路示意圖; 圖7是該第一較佳實施例於一開關元件導通時的一動作等效電路圖;圖8是該第一較佳實施例於該開關元件截止時的一動作等效電路圖;圖9是該第一較佳實施例的一較詳細的電路示意圖;圖10是該第一較佳實施例的一模擬波形圖;圖11是該第一較佳實施例的另一模擬波形圖;圖12是該第一較佳實施例的該調光訊號回復模組的另一樣態;圖13是該第一較佳實施例的第三模擬波形圖;圖14是該第一較佳實施例的第四模擬波形圖;及圖15是本發明發光二極體驅動電路之一第二較佳實施例的電路示意圖。Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a circuit diagram illustrating a conventional light-emitting diode using a buck converter and high-side switch drive technology. FIG. 2 is a circuit diagram illustrating a conventional LED driving circuit using a step-down converter and a floating grounding method; FIG. 3 is a circuit diagram illustrating a conventional transmission transformer using an isolation transformer FIG. 4 is a circuit diagram illustrating a conventional LED driving circuit using an optical coupler to transmit signals; FIG. 5 is a first preferred embodiment of the LED driving circuit of the present invention. FIG. 6 is a schematic circuit diagram of a dimming signal recovery module of the first preferred embodiment; FIG. FIG. 7 is an operational equivalent circuit diagram of the first preferred embodiment when a switching element is turned on; FIG. 8 is an operational equivalent circuit diagram of the first preferred embodiment when the switching element is turned off; FIG. A more detailed circuit diagram of the first preferred embodiment; FIG. 10 is an analog waveform diagram of the first preferred embodiment; FIG. 11 is another analog waveform diagram of the first preferred embodiment; Another mode of the dimming signal recovery module of the first preferred embodiment; FIG. 13 is a third analog waveform diagram of the first preferred embodiment; FIG. 14 is a fourth embodiment of the first preferred embodiment. Analog waveform diagram; and Fig. 15 is a circuit diagram showing a second preferred embodiment of a light-emitting diode driving circuit of the present invention.
在本發明被詳細描述之前,應當注意在以下的說明內容中,類似的元件是以相同的編號來表示。Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.
參閱圖5及圖6,本發明發光二極體驅動電路之第一較佳實施例適用於驅動複數發光二極體9,該發光二極體驅動電路包含:一電源電路2、一轉換電路3、一控制電路4,及一調光訊號位移電路5。Referring to FIG. 5 and FIG. 6 , the first preferred embodiment of the LED driving circuit of the present invention is suitable for driving a plurality of LEDs 9 . The LED driving circuit comprises: a power circuit 2 and a conversion circuit 3 . A control circuit 4 and a dimming signal shift circuit 5.
該電源電路2接收一交流電源Vac以輸出一電源訊號,該交流電源Vac具有一第一端201及一第二端202,該電源電路2包括一橋式整流模組21。The power circuit 2 receives an AC power supply Vac to output a power signal. The AC power supply Vac has a first end 201 and a second end 202. The power circuit 2 includes a bridge rectifier module 21.
該橋式整流模組21具有:一第一二極體D1、 一第二二極體D2、一第三二極體D3,及一第四二極體D4。The bridge rectifier module 21 has: a first diode D1 A second diode D2, a third diode D3, and a fourth diode D4.
該第一二極體D1具有一電連接該交流電源Vac的第一端201的陽極端,及一電連接該轉換電路3且輸出該電源訊號的陰極端。The first diode D1 has an anode end electrically connected to the first end 201 of the AC power source Vac, and a cathode end electrically connected to the conversion circuit 3 and outputting the power signal.
該第二二極體D2具有一電連接一接地端的陽極端,及一電連接該交流電源Vac的第一端的陰極端。The second diode D2 has an anode end electrically connected to a ground end, and a cathode end electrically connected to the first end of the alternating current power source Vac.
該第三二極體D3具有一電連接該交流電源Vac的第二端202的陽極端,及一電連接該轉換電路3且輸出該電源訊號的陰極端。The third diode D3 has an anode end electrically connected to the second end 202 of the AC power source Vac, and a cathode end electrically connected to the conversion circuit 3 and outputting the power signal.
該第四二極體D4具有一電連接該接地端的陽極端,及一電連接該交流電源Vac的第二端的陰極端。The fourth diode D4 has an anode end electrically connected to the ground end, and a cathode end electrically connected to the second end of the alternating current power source Vac.
該轉換電路3電連接於該電源電路2,並包括:一開關元件Q1、一輸出電容Co、一電感L,及一飛輪二極體Do。The conversion circuit 3 is electrically connected to the power supply circuit 2 and includes: a switching element Q1, an output capacitor Co, an inductor L, and a flywheel diode Do.
於本實施例中,使用降壓轉換電路(Buck Converter)來作為說明,但不限於此。In the present embodiment, a buck converter circuit is used as an explanation, but is not limited thereto.
該開關元件Q1具有一電連接該第三二極體D3的陰極端且接收該電源訊號的第一端、一第二端,及一接收一控制訊號的控制端,受控制而於導通與截止間切換。The switching element Q1 has a first end connected to the cathode end of the third diode D3 and receiving the power signal, a second end, and a control end receiving a control signal, which are controlled to be turned on and off. Switch between.
該輸出電容Co具有一提供一輸出電壓及輸出電流以驅動該等發光二極體9的第一端,及一接地的第二端。The output capacitor Co has a first end that provides an output voltage and an output current to drive the light emitting diodes 9, and a grounded second end.
該飛輪二極體Do具有一接地的陽極端,及一電 連接該開關元件Q1的第二端並提供一浮動接地電壓的陰極端。The flywheel diode Do has a grounded anode end and an electric A second end of the switching element Q1 is connected and a cathode terminal of a floating ground voltage is provided.
該電感L具有一電連接該飛輪二極體Do的陰極端的第一端,及一電連接該輸出電容Co的第一端的第二端。The inductor L has a first end electrically connected to the cathode end of the flywheel diode Do, and a second end electrically connected to the first end of the output capacitor Co.
該控制電路4包括:一開關元件控制端GATE、一參考浮動接地端VSS、一調光訊號輸入端DIM、一調光訊號回復模組41,及一調光控制模組42。The control circuit 4 includes a switching element control terminal GATE, a reference floating ground terminal VSS, a dimming signal input terminal DIM, a dimming signal recovery module 41, and a dimming control module 42.
該開關元件控制端GATE電連接該開關元件Q1的控制端且提供該控制訊號。The switching element control terminal GATE is electrically connected to the control terminal of the switching element Q1 and provides the control signal.
該參考浮動接地端VSS電連接於該電感L與該飛輪二極體Do之連接點,以接收該浮動接地電壓。The reference floating ground VSS is electrically connected to the connection point of the inductor L and the flywheel diode Do to receive the floating ground voltage.
該調光訊號輸入端DIM用以接收一對應該浮動接地電壓的調光輸入訊號。The dimming signal input terminal DIM is configured to receive a pair of dimming input signals that should be floating ground voltage.
該調光訊號回復模組41電連接該調光訊號輸入端DIM及該參考浮動接地端VSS,接收該調光輸入訊號並對該調光輸入訊號進行訊號回復後輸出。The dimming signal recovery module 41 is electrically connected to the dimming signal input terminal DIM and the reference floating ground terminal VSS, receives the dimming input signal, and outputs a signal to the dimming input signal.
該調光訊號回復模組41具有一比較器411,該比較器411接收該調光輸入訊號並與一預定電壓做比較,以輸出訊號回復後的該調光輸入訊號,於本實施例中,使用一預定電壓源Vf提供該預定電壓,但不以此為限。The dimming signal recovery module 41 has a comparator 411. The comparator 411 receives the dimming input signal and compares it with a predetermined voltage to output the dimming input signal after the signal is recovered. In this embodiment, The predetermined voltage is supplied using a predetermined voltage source Vf, but is not limited thereto.
該調光訊號回復模組41所輸出之訊號回復後的該調光輸入訊號,其脈波寬度及頻率實質上相同於該調光訊號。The dimming input signal after the signal outputted by the dimming signal recovery module 41 is restored has a pulse width and a frequency substantially the same as the dimming signal.
該調光控制模組42電連接該調光訊號回復模組41及該開關元件控制端GATE,接收訊號回復後的該調光輸入訊號,並根據回復後的該調光輸入訊號調整輸出該控制訊號。The dimming control module 42 is electrically connected to the dimming signal recovery module 41 and the switching element control terminal GATE, receives the dimming input signal after the signal is recovered, and adjusts and outputs the control according to the dimmed input signal after the reply. Signal.
該調光訊號位移電路5包括:一調光二極體Ddim及一調光電容Cdim。The dimming signal displacement circuit 5 includes: a dimming diode Ddim and a dimming capacitor Cdim.
該調光二極體Ddim具有一接收一對應該接地端電壓的調光訊號的陽極端,及一輸出對應該浮動接地電壓的該調光輸入訊號的陰極端。The dimming diode Ddim has an anode terminal that receives a pair of dimming signals that should have a ground voltage, and an anode terminal that outputs the dimming input signal corresponding to the floating ground voltage.
該調光電容Cdim具有一電連接該調光二極體Ddim的陰極端的第一端,及一接收該浮動接地電壓的第二端。The dimming capacitor Cdim has a first end electrically connected to the cathode end of the dimming diode Ddim, and a second end receiving the floating ground voltage.
參閱圖7及圖8,分別為開關元件Q1導通及截止時的等效電路圖,為使圖示清晰明瞭,於圖7及圖8中,該交流電源Vac與該電源電路2以一全波整流後之等效電源Vref做為代表。7 and FIG. 8, which are equivalent circuit diagrams when the switching element Q1 is turned on and off, respectively, in order to make the figure clear, in FIG. 7 and FIG. 8, the AC power supply Vac and the power supply circuit 2 are fully wave rectified. The equivalent power supply Vref is used as a representative.
如圖7所示,當該開關元件Q1導通時,該飛輪二極體Do截止,此時該開關元件Q1的第二端為相對高電位,故該調光訊號位移電路5由於調光二極體Ddim逆向偏壓而截止,且該全波整流後之等效電源Vref對該電感L儲存能量。As shown in FIG. 7, when the switching element Q1 is turned on, the flywheel diode Do is turned off, and at this time, the second end of the switching element Q1 is relatively high, so the dimming signal shifting circuit 5 is dimmed due to the dipole The body Ddim is reverse biased and turned off, and the full-wave rectified equivalent power source Vref stores energy for the inductor L.
如圖8所示,當該開關元件Q1截止時,該電感L透過該飛輪二極體Do釋能而使該飛輪二極體Do導通,此時該開關元件Q1的第二端為等效接地而為相對低電位 ,故該調光訊號位移電路5中之調光二極體Ddim順向偏壓而導通,使得對應該接地端電壓之調光訊號得以傳送到調光電容Cdim上,令該調光電容Cdim的跨壓約等於該調光訊號的電壓峰值。As shown in FIG. 8, when the switching element Q1 is turned off, the inductor L is turned on by the flywheel diode Do to turn on the flywheel diode Do. At this time, the second end of the switching element Q1 is equivalently grounded. Relatively low potential Therefore, the dimming diode Ddim in the dimming signal shifting circuit 5 is forward biased and turned on, so that the dimming signal corresponding to the grounding voltage is transmitted to the dimming capacitor Cdim, so that the dimming capacitor Cdim The voltage across the voltage is approximately equal to the voltage peak of the dimming signal.
由於該轉換電路3的降壓轉換為此業界所熟知,在此並不贅述。Since the buck conversion of the conversion circuit 3 is well known in the art, it will not be described here.
參閱圖5及圖6,該調光訊號位移電路5於接收對應接地端電壓的該調光訊號後,藉由該調光二極體Ddim及接收該浮動接地電壓的調光電容Cdim,可以將該調光訊號調整為對應該浮動接地電壓的調光輸入訊號,再經由該調光訊號回復模組41的比較器411與該預定電壓做比較後,即可得到訊號回復後的該調光輸入訊號。Referring to FIG. 5 and FIG. 6 , the dimming signal displacement circuit 5 can receive the dimming signal corresponding to the ground voltage, and the dimming diode Ddim and the dimming capacitor Cdim receiving the floating ground voltage can be used. The dimming signal is adjusted to a dimming input signal corresponding to the floating ground voltage, and the comparator 411 of the dimming signal recovery module 41 is compared with the predetermined voltage to obtain the dimming input after the signal is recovered. Signal.
參閱圖6及圖9,其中圖9為本實施例之較詳細的電路示意圖,其中:該控制電路4還包括:一用以接收電源的電源端VDD、一迴授端FB,及一相位補償端COMP,該電源端VDD用以提供控制電路4所需之電源,該迴授端FB用以接收對應於電感L電流及該輸出電流之一迴授訊號,該相位補償端COMP用以補償該迴授訊號之相位,使系統穩定。該控制電路4藉由所接收到之迴授訊號控制開關元件Q1導通與截止,並使轉換電路3輸出穩定之該輸出電流以驅動該發光二極體模組9。Referring to FIG. 6 and FIG. 9 , FIG. 9 is a schematic diagram of a more detailed circuit of the embodiment, wherein the control circuit 4 further includes: a power terminal VDD for receiving power, a feedback terminal FB, and a phase compensation. The power supply terminal VDD is used to supply the power required by the control circuit 4, and the feedback terminal FB is configured to receive a feedback signal corresponding to the inductor L current and the output current, and the phase compensation terminal COMP is used to compensate the The phase of the feedback signal makes the system stable. The control circuit 4 controls the switching element Q1 to be turned on and off by the received feedback signal, and causes the conversion circuit 3 to output the stable output current to drive the LED module 9.
該電源電路2還包括一電磁干擾濾波模組22及一濾波電容C1。The power circuit 2 further includes an electromagnetic interference filter module 22 and a filter capacitor C1.
該電磁干擾濾波模組22具有:一電磁干擾濾波電感Lf及一電磁干擾濾波電容Cf。The electromagnetic interference filter module 22 has an electromagnetic interference filter inductor Lf and an electromagnetic interference filter capacitor Cf.
該電磁干擾濾波電感Lf具有一電連接該交流電源Vac的第一端201的第一端,及一電連接該第一二極體D1的陽極端的第二端。The electromagnetic interference filter inductor Lf has a first end electrically connected to the first end 201 of the AC power source Vac, and a second end electrically connected to the anode end of the first diode D1.
該電磁干擾濾波電容Cf具有一電連接該電磁干擾濾波電感Lf的第二端的第一端,及一電連接該交流電源Vac的第二端202的第二端。The EMI filter capacitor Cf has a first end electrically connected to the second end of the EMI filter inductor Lf, and a second end electrically connected to the second end 202 of the AC power source Vac.
值得一提的是,於本實施例中,該電磁干擾濾波模組22僅以一電磁干擾濾波電感Lf及一電磁干擾濾波電容Cf作為示意,主要是作為電磁干擾濾波器(EMI Filter),然而電磁干擾濾波器具有多種實施態樣,本領域中具有相關知識者亦可依此變化,不以此為限。It is to be noted that, in this embodiment, the electromagnetic interference filter module 22 is only illustrated by an electromagnetic interference filter inductor Lf and an electromagnetic interference filter capacitor Cf, mainly as an electromagnetic interference filter (EMI Filter). The EMI filter has various implementations, and those skilled in the art may also change accordingly, and are not limited thereto.
該濾波電容C1具有一電連接該開關元件Q1的第一端的第一端,及一電連接該接地端的第二端。The filter capacitor C1 has a first end electrically connected to the first end of the switching element Q1, and a second end electrically connected to the ground end.
該轉換電路3還包括一迴授電阻Rfb,該迴授電阻Rfb串接於該電感L及該飛輪二極體Do間,用以產生對應電感L電流及輸出電流的該迴授訊號,並輸入到該迴授端FB,以達到電感L電流及輸出電流之迴授控制。The conversion circuit 3 further includes a feedback resistor Rfb connected in series between the inductor L and the flywheel diode Do to generate the feedback signal corresponding to the inductor L current and the output current, and input Go to the feedback terminal FB to achieve the feedback control of the inductor L current and the output current.
參閱圖6、圖9及圖10,圖10所示為使用圖6、圖9的電路所進行的模擬波形圖,其中,曲線91為所輸入的調光訊號,且其導通率(duty ratio)為90%,頻率為600Hz,經由該調光訊號位移電路5對應該浮動接地電壓處理後,所輸出之調光輸入訊號即曲線92,由圖10中可見, 由於該浮動接地電壓的影響,曲線92與曲線91的最低電位並不相同,且曲線92的高電位值亦會有浮動的現象,再經由該調光訊號回復模組41處理後,所得之訊號回復後的該調光輸入訊號即曲線93,由圖10中可見,訊號回復後的該調光輸入訊號(曲線93)之脈波寬度及頻率皆相同於該調光訊號(曲線91)。Referring to FIG. 6, FIG. 9, and FIG. 10, FIG. 10 is an analog waveform diagram performed by using the circuits of FIG. 6 and FIG. 9, wherein the curve 91 is the input dimming signal, and its duty ratio is (duty ratio). 90%, the frequency is 600Hz, after the dimming signal displacement circuit 5 corresponds to the floating ground voltage processing, the output dimming input signal is the curve 92, as can be seen in FIG. Due to the influence of the floating ground voltage, the lowest potential of the curve 92 and the curve 91 are not the same, and the high potential value of the curve 92 also has a floating phenomenon, and the signal obtained by the dimming signal recovery module 41 is processed. The dimming input signal after the reply is the curve 93. As can be seen from FIG. 10, the pulse width and frequency of the dimming input signal (curve 93) after the signal is recovered are the same as the dimming signal (curve 91).
參閱圖6、圖9及圖11,圖11所示為使用圖6、圖9的電路所進行的模擬波形圖,其中,曲線91為所輸入的調光訊號,且其導通率為10%,頻率為600Hz,曲線92為該調光訊號位移電路5對應該浮動接地電壓處理後的調光輸入訊號,曲線93為經該調光訊號回復模組41處理後之訊號回復後的調光輸入訊號,由圖11中可見,訊號回復後的該調光輸入訊號(曲線93)之脈波寬度及頻率亦皆相同於該調光訊號(曲線91)。Referring to FIG. 6 , FIG. 9 and FIG. 11 , FIG. 11 is an analog waveform diagram performed by using the circuits of FIG. 6 and FIG. 9 , wherein the curve 91 is the input dimming signal, and the conduction rate is 10%. The frequency is 600 Hz, the curve 92 is the dimming input signal processed by the dimming signal displacement circuit 5 corresponding to the floating ground voltage, and the curve 93 is the dimming input signal after the signal processed by the dimming signal recovery module 41 is recovered. As can be seen from FIG. 11, the pulse width and frequency of the dimming input signal (curve 93) after the signal is recovered are also the same as the dimming signal (curve 91).
參閱圖12,為該第一實施例中該調光訊號回復模組41的另一樣態,此樣態與該第一實施例的差異處在於:該比較器411具有一正相輸入端及一反相輸入端。Referring to FIG. 12, another aspect of the dimming signal recovery module 41 in the first embodiment is different from the first embodiment in that the comparator 411 has a positive phase input terminal and a Inverting input.
該調光訊號回復模組41還具有:一取樣二極體Dsh、一取樣電容Csh,及一預定電壓源Vf。The dimming signal recovery module 41 further has a sampling diode Dsh, a sampling capacitor Csh, and a predetermined voltage source Vf.
該取樣二極體Dsh具有一接收該調光輸入訊號的陽極端,及一電連接該比較器411正相輸入端的陰極端。The sampling diode Dsh has an anode terminal for receiving the dimming input signal and a cathode terminal electrically connected to the positive phase input terminal of the comparator 411.
該取樣電容Csh具有一電連接該取樣二極體Dsh的陰極端的第一端,及一接收該浮動接地電壓的第二端。The sampling capacitor Csh has a first end electrically connected to the cathode end of the sampling diode Dsh, and a second end receiving the floating ground voltage.
該預定電壓源Vf具有一電連接該比較器411反相輸入端並提供該預定電壓的第一端,及一電連接該取樣電容Csh的第二端的第二端。The predetermined voltage source Vf has a first end electrically connected to the inverting input terminal of the comparator 411 and providing the predetermined voltage, and a second end electrically connected to the second end of the sampling capacitor Csh.
於此樣態中,藉由加入該取樣二極體Dsh及該取樣電容Csh,可以提供取樣及保持(Sample & Hold)的功效,避免當比較器411特性較差(輸入阻抗不夠大)時產生負載效應而造成該調光輸入訊號失真。In this aspect, by adding the sampling diode Dsh and the sampling capacitor Csh, the sample & hold function can be provided to avoid the load when the comparator 411 has poor characteristics (the input impedance is not large enough). The effect causes the dimming input signal to be distorted.
參閱圖9、圖13及圖14,其中,圖13、圖14所示為使用圖9、圖12的電路所進行的模擬波形圖,曲線91為所輸入的調光訊號、曲線92為調光輸入訊號,曲線93為訊號回復後的該調光輸入訊號,圖13中曲線91之調光訊號的導通率為90%,頻率為600Hz,圖14中曲線91之調光訊號的導通率為10%,頻率為600Hz,由圖13及圖14中可見,經由該調光訊號位移電路5及該調光訊號回復模組41處理後,所得到訊號回復後的該調光輸入訊號(曲線93)之脈波寬度及頻率皆相同於該調光訊號(曲線91)。Referring to FIG. 9 , FIG. 13 and FIG. 14 , FIG. 13 and FIG. 14 show analog waveform diagrams performed by using the circuits of FIG. 9 and FIG. 12 , curve 91 is the input dimming signal, and curve 92 is dimming. Input signal, curve 93 is the dimming input signal after the signal is recovered. The conduction signal of the dimming signal of curve 91 in FIG. 13 is 90%, the frequency is 600 Hz, and the conductivity of the dimming signal of curve 91 in FIG. 14 is 10 %, the frequency is 600 Hz, as seen in FIG. 13 and FIG. 14 , after the dimming signal displacement circuit 5 and the dimming signal recovery module 41 are processed, the dimming input signal after the obtained signal is recovered (curve 93) The pulse width and frequency are the same as the dimming signal (curve 91).
經由以上的說明,可將本實施例的優點歸納如下:Through the above description, the advantages of this embodiment can be summarized as follows:
一、藉由使用該調光電容Cdim及該調光二極體Ddim,即可取代習知技術中的隔離變壓器或光耦合器,不但可以大量節省電路體積、減少電路元件,進而大幅降低 電路成本,且本實施例可應用於高端開關驅動技術或是浮動接地方式,在控制電路4的參考浮動接地端VSS所接收的浮動接地電壓與接地端的電壓不相同時,仍可在傳遞過程中沒有統一的參考接地電位可供參考的情況下正常偵測或傳遞訊號。1. By using the dimming capacitor Cdim and the dimming diode Ddim, the isolation transformer or the optical coupler in the prior art can be replaced, which can save a large amount of circuit volume and reduce circuit components, thereby greatly reducing Circuit cost, and the embodiment can be applied to the high-side switch drive technology or the floating grounding mode. When the floating ground voltage received by the reference floating ground terminal VSS of the control circuit 4 is different from the voltage of the ground terminal, the transmission process can still be performed. Normally detect or transmit signals without a uniform reference ground potential for reference.
二、由圖9中可得知,交流電源Vac在經過該電源電路2整流濾波處理後已轉為直流電源,因此當本實施例要應用於直流電壓輸入時,只需省略該電源電路2,即可由該開關元件Q1的第一端直接接收直流的電源訊號,可增加應用上的靈活度。2. It can be seen from FIG. 9 that the AC power supply Vac has been converted to a DC power supply after being rectified and filtered by the power supply circuit 2. Therefore, when the present embodiment is to be applied to a DC voltage input, the power supply circuit 2 only needs to be omitted. The DC power signal can be directly received by the first end of the switching element Q1, which can increase the flexibility of the application.
參閱圖15,為本發明發光二極體驅動電路的一第二較佳實施例,該第二較佳實施例是類似於該第一較佳實施例的詳細電路圖,該第二較佳實施例與該第一較佳實施例的差異在於:於該轉換電路3中,該飛輪二極體Do具有一電連接該輸出電容Co的第一端的陽極端,及一陰極端;該電感L具有一電連接該開關元件Q1的第二端的第一端,及一接地的第二端;該迴授電阻Rfb串接於該飛輪二極體Do的陰極端及該繞組L的第一端間。15 is a second preferred embodiment of a light emitting diode driving circuit of the present invention. The second preferred embodiment is a detailed circuit diagram similar to the first preferred embodiment. The second preferred embodiment The difference from the first preferred embodiment is that in the conversion circuit 3, the flywheel diode Do has an anode end electrically connected to the first end of the output capacitor Co, and a cathode end; the inductor L has A first end electrically connected to the second end of the switching element Q1 and a second end connected to the ground; the feedback resistor Rfb is connected in series between the cathode end of the flywheel diode Do and the first end of the winding L.
於本實施例中,使用降升壓轉換電路(Buck-Boost Converter)來作為說明,但不限於此。In the present embodiment, a buck-boost converter is used as an explanation, but is not limited thereto.
由於該轉換電路3的降升壓轉換為此業界所熟知,且該控制電路4及該調光訊號位移電路5之運作方式類似於上述,故在此不再贅言。Since the step-down conversion of the conversion circuit 3 is well known in the art, and the operation mode of the control circuit 4 and the dimming signal shift circuit 5 is similar to the above, it is no longer mentioned herein.
如此,該第二較佳實施例亦可達到與上述第一較佳實施例相同的目的與功效。Thus, the second preferred embodiment can achieve the same purpose and effect as the first preferred embodiment described above.
綜上所述,本發明不僅可以節省電路體積及成本、降低設計複雜度,還可提升系統可靠度、增加應用上的靈活度,故確實能達成本發明之目的。In summary, the present invention can not only save circuit volume and cost, reduce design complexity, but also improve system reliability and increase application flexibility, so that the object of the present invention can be achieved.
惟以上所述者,僅為本發明之較佳實施例而已,當不能以此限定本發明實施之範圍,即大凡依本發明申請專利範圍及專利說明書內容所作之簡單的等效變化與修飾,皆仍屬本發明專利涵蓋之範圍內。The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.
2‧‧‧電源電路2‧‧‧Power circuit
Vac‧‧‧交流電源Vac‧‧‧AC power supply
201‧‧‧交流電源之第一端201‧‧‧The first end of the AC power supply
202‧‧‧交流電源之第二端202‧‧‧The second end of the AC power supply
21‧‧‧橋式整流模組21‧‧‧Bridge rectifier module
D1‧‧‧第一二極體D1‧‧‧First Diode
D2‧‧‧第二二極體D2‧‧‧ second diode
D3‧‧‧第三二極體D3‧‧‧ third diode
D4‧‧‧第四二極體D4‧‧‧ fourth diode
3‧‧‧轉換電路3‧‧‧Transition circuit
Q1‧‧‧開關元件Q1‧‧‧Switching elements
L‧‧‧電感L‧‧‧Inductance
Do‧‧‧飛輪二極體Do‧‧‧Flywheel diode
Co‧‧‧輸出電容Co‧‧‧ output capacitor
4‧‧‧控制電路4‧‧‧Control circuit
VSS‧‧‧參考浮動接地端VSS‧‧‧reference floating ground
DIM‧‧‧調光訊號輸入端DIM‧‧‧ dimming signal input
GATE‧‧‧開關元件控制端GATE‧‧‧ switching element control terminal
41‧‧‧調光訊號回復模組41‧‧‧ Dimming signal recovery module
42‧‧‧調光控制模組42‧‧‧ dimming control module
5‧‧‧調光訊號位移電路5‧‧‧ dimming signal displacement circuit
Cdim‧‧‧調光電容Cdim‧‧‧ dimming capacitor
Ddim‧‧‧調光二極體Ddim‧‧‧ dimming diode
9‧‧‧發光二極體9‧‧‧Lighting diode
Claims (10)
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TW102132236A TWI489908B (en) | 2013-09-06 | 2013-09-06 | Light emitting diode drive circuit |
CN201410400736.8A CN104427716B (en) | 2013-09-06 | 2014-08-13 | Light emitting diode driving circuit |
Applications Claiming Priority (1)
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TW102132236A TWI489908B (en) | 2013-09-06 | 2013-09-06 | Light emitting diode drive circuit |
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TW201511608A TW201511608A (en) | 2015-03-16 |
TWI489908B true TWI489908B (en) | 2015-06-21 |
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TW102132236A TWI489908B (en) | 2013-09-06 | 2013-09-06 | Light emitting diode drive circuit |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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TWI669987B (en) * | 2018-05-11 | 2019-08-21 | 群光電能科技股份有限公司 | Light source switching system |
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KR101969042B1 (en) * | 2016-04-26 | 2019-04-15 | 솔로몬 시스테크 리미티드 | Method and apparatus of a multi-phase convertor topology |
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TWM366853U (en) * | 2009-01-05 | 2009-10-11 | Cal Comp Electronics & Comm Co | Light-emitting device |
CN102052592A (en) * | 2009-11-10 | 2011-05-11 | 新绿科技股份有限公司 | Dimmable led lamp |
TWM423415U (en) * | 2011-10-05 | 2012-02-21 | Darfon Electronics Corp | Non-isolated buck-boost light emitting diode driving circuit |
TW201251501A (en) * | 2011-06-08 | 2012-12-16 | Macroblock Inc | Light emitting diode driving circuit for AC or DC power source |
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TWM366853U (en) * | 2009-01-05 | 2009-10-11 | Cal Comp Electronics & Comm Co | Light-emitting device |
CN102052592A (en) * | 2009-11-10 | 2011-05-11 | 新绿科技股份有限公司 | Dimmable led lamp |
TW201251501A (en) * | 2011-06-08 | 2012-12-16 | Macroblock Inc | Light emitting diode driving circuit for AC or DC power source |
TWM423415U (en) * | 2011-10-05 | 2012-02-21 | Darfon Electronics Corp | Non-isolated buck-boost light emitting diode driving circuit |
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TWI669987B (en) * | 2018-05-11 | 2019-08-21 | 群光電能科技股份有限公司 | Light source switching system |
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CN104427716A (en) | 2015-03-18 |
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