TWM569122U

TWM569122U - LED driving circuit

Info

Publication number: TWM569122U
Application number: TW107209927U
Authority: TW
Inventors: 劉拓夫; 周俊
Original assignee: 大陸商昂寶電子（上海）有限公司
Priority date: 2018-06-07
Filing date: 2018-07-20
Publication date: 2018-10-21
Also published as: CN208509320U

Abstract

一種LED驅動電路，包括交流(AC)輸入整流電路、緩亮控制電路、以及輸出濾波電路，其中：AC輸入整流電路具有四個整流電路端子，第一和第二整流電路端子用於分別連接AC電源的正極和負極，第三整流電路端子與緩亮控制電路的第一控制電路端子連接，第四整流電路端子接地；緩亮控制電路具有四個控制電路端子，第一控制電路端子與第三整流電路端子連接，第二控制電路端子接基準地，第三控制電路端子與輸出濾波電路的第一濾波電路端子連接，第四控制電路端子與輸出濾波電路的第二濾波電路端子連接並接地；輸出濾波電路具有兩個濾波電路端子，第一和第二濾波電路端子分別與第三和第四控制電路端子連接，該兩個濾波電路端子用於分別連接LED負載的兩端。 An LED driving circuit comprises an alternating current (AC) input rectifying circuit, a slow lighting control circuit, and an output filtering circuit, wherein: the AC input rectifying circuit has four rectifying circuit terminals, and the first and second rectifying circuit terminals are respectively connected to the AC The positive and negative poles of the power supply, the third rectifier circuit terminal is connected to the first control circuit terminal of the slow control circuit, the fourth rectifier circuit terminal is grounded; the slow control circuit has four control circuit terminals, the first control circuit terminal and the third The rectifier circuit terminal is connected, the second control circuit terminal is connected to the reference ground, the third control circuit terminal is connected to the first filter circuit terminal of the output filter circuit, and the fourth control circuit terminal is connected to the second filter circuit terminal of the output filter circuit and grounded; The output filter circuit has two filter circuit terminals, and the first and second filter circuit terminals are respectively connected to the third and fourth control circuit terminals, and the two filter circuit terminals are used to respectively connect the two ends of the LED load.

Description

LED驅動電路 LED drive circuit

本新型涉及電路領域，更具體地涉及一種能夠實現LED緩亮方案的LED驅動電路。 The present invention relates to the field of circuits, and more particularly to an LED driving circuit capable of implementing an LED backlighting scheme.

隨著發光二極體(Light-emitting diode，LED)驅動器的發展，LED緩亮方案逐漸成為人們比較青睞的一種LED驅動方案。LED緩亮方案與傳統的LED驅動方案的不同在於，在LED開啟後不會直接達到最大亮度，而是從低亮度漸變至最大亮度，以給人眼一定的適應時間，這樣可以起到保護人眼的作用。 With the development of Light-emitting Diode (LED) drivers, LED slow-lighting solutions have gradually become an LED driver solution that people prefer. The LED slow-lighting scheme differs from the traditional LED driving scheme in that it does not directly reach the maximum brightness after the LED is turned on, but gradually changes from low brightness to maximum brightness to give the human eye a certain adaptation time, which can protect the person. The role of the eye.

目前的LED緩亮方案通常需要額外的電路(例如，微控制單元(MCU))來控制LED的亮度變化，在成本以及體積上都沒有任何優勢。所以，需要一種新型的低成本、小體積的LED緩亮方案。 Current LED backlighting schemes typically require additional circuitry (eg, a Micro Control Unit (MCU)) to control the brightness variation of the LEDs, with no cost or size advantages. Therefore, there is a need for a new low-cost, small-volume LED backlighting solution.

鑒於以上所述的一個或多個問題，本新型提供了一種能夠實現LED緩亮方案的LED驅動電路。 In view of one or more of the problems described above, the present invention provides an LED drive circuit capable of implementing an LED backlighting scheme.

根據本新型實施例的LED驅動電路，包括交流(AC)輸入整流電路、緩亮控制電路、以及輸出濾波電路，其中：AC輸入整流電路具有四個整流電路端子，第一和第二整流電路端子用於分別連接AC電源的正極和負極，第三整流電路端子與緩亮控制電路的第一控制電路端子連接，第四整流電路端子接地；緩亮控制電路具有四個控制電路端子，第一控制電路端子與第三整流電路端子連接，第二控制電路端子接基準地，第三控制電路端子與輸出濾波電路的第一濾波電路端子連接，第四控制電路端子與輸出濾波電路的第二濾波電路端子連接並接地；輸出濾波電路具有兩個濾波電路端子，第一濾波電路端子與第三控制電路端子連接，第二濾波電路端子與第四控制電路端子連接並接地，該兩個濾波電路端子用於分別連接LED負載的兩端。 An LED driving circuit according to an embodiment of the present invention includes an alternating current (AC) input rectifying circuit, a slow lighting control circuit, and an output filter circuit, wherein: the AC input rectifying circuit has four rectifying circuit terminals, first and second rectifying circuit terminals For respectively connecting the positive and negative poles of the AC power source, the third rectifier circuit terminal is connected to the first control circuit terminal of the lightening control circuit, the fourth rectifier circuit terminal is grounded; the brightness control circuit has four control circuit terminals, the first control The circuit terminal is connected to the third rectifier circuit terminal, the second control circuit terminal is connected to the reference ground, the third control circuit terminal is connected to the first filter circuit terminal of the output filter circuit, and the fourth control circuit terminal and the second filter circuit of the output filter circuit are The terminal is connected and grounded; the output filter circuit has two filter circuit terminals, the first filter circuit terminal is connected to the third control circuit terminal, the second filter circuit terminal is connected to the fourth control circuit terminal and grounded, and the two filter circuit terminals are Used to connect the two ends of the LED load separately.

根據本新型實施例的LED驅動電路，能夠使LED在開啟後不會直接達到最大亮度，而是從低亮度漸變至最大亮度，並具有小體積和低成本的優點。 The LED driving circuit according to the embodiment of the present invention can make the LED not directly reach the maximum brightness after being turned on, but gradually changes from low brightness to maximum brightness, and has the advantages of small volume and low cost.

102‧‧‧(AC)輸入整流電路 102‧‧‧(AC) input rectifier circuit

104‧‧‧緩亮控制電路 104‧‧‧Slow control circuit

106‧‧‧輸出濾波電路 106‧‧‧Output filter circuit

F1‧‧‧保險絲 F1‧‧‧Fuse

D1、D2、D3、D4‧‧‧整流二極體 D1, D2, D3, D4‧‧‧ Rectifiers

C1‧‧‧輸入濾波電容 C1‧‧‧ input filter capacitor

U1‧‧‧緩亮控制晶片 U1‧‧‧Slow control chip

R1、R2、R3、R4‧‧‧電阻 R1, R2, R3, R4‧‧‧ resistance

C2‧‧‧晶片供電電容 C2‧‧‧ wafer supply capacitor

DRAIN‧‧‧晶片內部高壓MOS管的汲極腳 DRAIN‧‧‧ wafer internal high voltage MOS tube

FB‧‧‧退磁感測及開路保護腳 FB‧‧‧Demagnetization sensing and open circuit protection feet

VDD‧‧‧晶片供電腳 VDD‧‧‧ chip power supply

CS‧‧‧LED電流設定腳 CS‧‧‧LED current setting foot

FT‧‧‧緩亮時間設定腳 FT‧‧‧Slow time setting foot

GND‧‧‧晶片基準地 GND‧‧‧ wafer reference ground

D5‧‧‧續流二極體 D5‧‧‧ Freewheeling diode

L1‧‧‧功率電感 L1‧‧‧Power Inductors

C4‧‧‧輸出濾波電容 C4‧‧‧ Output Filter Capacitor

C3‧‧‧緩亮時間控制電容 C3‧‧‧Lighting time control capacitor

從下面結合附圖對本新型的具體實施方式的描述中可以更好地理解本新型，其中： The present invention can be better understood from the following description of the specific embodiments of the present invention, in which:

第1圖是示出根據本新型實施例的LED驅動電路的電路圖。 Fig. 1 is a circuit diagram showing an LED driving circuit according to an embodiment of the present invention.

現在，將參考附圖更全面地描述示例實施方式。然而，示例實施方式能夠以多種形式實施，且不應被理解為限於在此闡述的實施方式；相反，提供這些實施方式使得本新型更全面和完整，並將示例實施方式的構思全面地傳達給本領域的技術人員。在圖中，為了清晰，可能誇大了區域和層的厚度。在圖中相同的附圖標記表示相同或類似的結構，因而將省略它們的詳細描述。 Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be embodied in a variety of forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the example embodiments. Those skilled in the art. In the figures, the thickness of the regions and layers may be exaggerated for clarity. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

此外，所描述的特徵、結構、或特性可以以任何合適的方式結合在一個或更多實施例中。在下面的描述中，提供許多具體細節從而給出對本新型的實施例的充分理解。然而，本領域技術人員將意識到，可以實踐本新型的技術方案而沒有所述特定細節中的一個或更多，或者可以採用其它的方法、組元、材料等。在其它情況下，不詳細示出或描述公知結構、材料、或者操作以避免模糊本新型的主要技術創意。 Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are set forth in the However, those skilled in the art will appreciate that the technical solution of the present invention may be practiced without one or more of the specific details, or other methods, components, materials, and the like may be employed. In other instances, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring the invention.

第1圖是示出根據本新型實施例的LED驅動電路的電路圖。如第1圖所示，根據本新型實施例的LED驅動電路是基於BUCK電路結構的LED驅動電路，並且包括交流(AC)輸入整流電路102、緩亮控制電路104、以及輸出濾波電路106，其中：AC輸入整流電路102具有四個整流電路端子，第一和第二整流電路端子用於分別連接AC電源的正極和負極，第三整流電路端子與緩亮控制電路104的第一控制電路端子連接，第四整流電路端子接地。 Fig. 1 is a circuit diagram showing an LED driving circuit according to an embodiment of the present invention. As shown in FIG. 1, the LED driving circuit according to the embodiment of the present invention is an LED driving circuit based on a BUCK circuit structure, and includes an alternating current (AC) input rectifying circuit 102, a dimming control circuit 104, and an output filter circuit 106, wherein The AC input rectifier circuit 102 has four rectifier circuit terminals, the first and second rectifier circuit terminals are respectively connected to the positive and negative poles of the AC power source, and the third rectifier circuit terminal is connected to the first control circuit terminal of the brightness control circuit 104. The fourth rectifier circuit terminal is grounded.

緩亮控制電路104具有四個控制電路端子，第一控制電路端子與AC輸入整流電路102的第三整流電路端子連接，第二控制電路端子接基準地，第三控制電路端子與輸出濾波電路106的第一濾波電路端子連接，第四控制電路端子與輸出濾波電路106的第二濾波電路端子連接並接地。 The slow control circuit 104 has four control circuit terminals, the first control circuit terminal is connected to the third rectifier circuit terminal of the AC input rectifier circuit 102, the second control circuit terminal is connected to the reference ground, and the third control circuit terminal and the output filter circuit 106 are connected. The first filter circuit terminal is connected, and the fourth control circuit terminal is connected to the second filter circuit terminal of the output filter circuit 106 and grounded.

輸出濾波電路106具有兩個濾波電路端子，第一濾波電路端子與緩亮控制電路104的第三控制電路端子連接，第二濾波電路端子與緩亮控制電路104的第四控制電路端子連接並接地。這裡，輸出濾波電路106的兩個濾波電路端子用於分別連接LED負載的兩端。 The output filter circuit 106 has two filter circuit terminals, the first filter circuit terminal is connected to the third control circuit terminal of the brightness control circuit 104, and the second filter circuit terminal is connected to the fourth control circuit terminal of the brightness control circuit 104 and grounded. . Here, the two filter circuit terminals of the output filter circuit 106 are used to respectively connect the two ends of the LED load.

在一些實施例中，AC輸入整流電路102包括保險絲F1，整流二極體D1、D2、D3、D4，以及輸入濾波電容C1。緩亮控制電路104包括緩亮控制晶片U1，高壓啟動電阻R1，電流感測電阻R2，退磁感測及開路保護設置電阻R3和R4，晶片供電電容C2，緩亮時間控制電容C3，續流二極體D5，以及功率電感L1。輸出濾波電路106包括輸出濾波電容C4。 In some embodiments, the AC input rectification circuit 102 includes a fuse F1, rectifying diodes D1, D2, D3, D4, and an input filter capacitor C1. The brightness control circuit 104 includes a slow control chip U1, a high voltage start resistor R1, a current sense resistor R2, a demagnetization sense and an open circuit protection set resistor R3 and R4, a chip supply capacitor C2, a slow time control capacitor C3, and a freewheeling Polar body D5, and power inductor L1. Output filter circuit 106 includes an output filter capacitor C4.

在一些實施例中，緩亮控制晶片U1包括晶片內部高壓MOS管的汲極腳(DRAIN腳)、晶片供電腳(VDD腳)、退磁感測及開路保護腳(FB腳)、LED電流設定腳(CS腳)、緩亮時間設定腳(FT腳)、以及晶片基準地(GND腳)。這裡，緩亮控制晶片U1的GND腳可以與緩亮控制電路104的第二控制電路端子連接或者作為緩亮控制電路104的第二控制電路端子。 In some embodiments, the backlight control wafer U1 includes a drain pin (DRAIN pin), a chip supply pin (VDD pin), a demagnetization sense and an open protection pin (FB pin), and an LED current setting pin of the internal high voltage MOS transistor of the wafer. (CS pin), lightening time setting pin (FT pin), and wafer reference ground (GND pin). Here, the GND pin of the backlight control wafer U1 may be connected to the second control circuit terminal of the backlight control circuit 104 or as the second control circuit terminal of the backlight control circuit 104.

具體地，緩亮控制晶片U1的工作過程如下： Specifically, the working process of the backlight control wafer U1 is as follows:

第一階段，在上電後，將LED驅動電路的輸出電壓預沖至略小於LED導通電壓的電壓。 In the first stage, after power-on, the output voltage of the LED driving circuit is pre-pulsed to a voltage slightly smaller than the LED conducting voltage.

第二階段，對緩亮控制電容C3充電，使得緩亮控制電容C3上的電壓隨時間升高；通過檢測緩亮控制電容C3上的電壓來控制LED驅動電路的輸出電流的大小，使得LED驅動電路的輸出電流的大小隨緩亮控制電容C3上的電壓的升高而增大，以實現LED的緩亮控制。這裡，緩亮控制電容C3的電容大小決定了LED緩亮過程的時間長短。 In the second stage, the slow control capacitor C3 is charged, so that the voltage on the slow control capacitor C3 rises with time; the output current of the LED driving circuit is controlled by detecting the voltage on the slow control capacitor C3, so that the LED driver The magnitude of the output current of the circuit increases as the voltage on the slow control capacitor C3 increases to achieve LED backlighting control. Here, the size of the capacitance of the backlight control capacitor C3 determines the length of time during which the LED is slowed down.

第三階段，對緩亮控制電容C3充電至一定電壓並保持，使得LED的亮度達到最大亮度並保持該最大亮度。 In the third stage, the slow control capacitor C3 is charged to a certain voltage and held, so that the brightness of the LED reaches the maximum brightness and maintains the maximum brightness.

本新型可以以其他的具體形式實現，而不脫離其精神和本質特徵。因此，當前的實施例在所有方面都應該被看作是示例性的而非限定性的，本新型的範圍由所附權利要求而非上述描述定義，並且，落入權利要求的含義和等同物的範圍內的全部改變都被包括在本新型的範圍之中。 The present invention may be embodied in other specific forms without departing from the spirit and essential characteristics. The present embodiments are to be considered in all respects as illustrative and not restrict All changes within the scope of the invention are included in the scope of the present invention.

Claims

一種LED驅動電路，包括交流(AC)輸入整流電路、緩亮控制電路、以及輸出濾波電路，其中：所述AC輸入整流電路具有四個整流電路端子，第一和第二整流電路端子用於分別連接AC電源的正極和負極，第三整流電路端子與所述緩亮控制電路的第一控制電路端子連接，第四整流電路端子接地；所述緩亮控制電路具有四個控制電路端子，所述第一控制電路端子與所述第三整流電路端子連接，第二控制電路端子接基準地，第三控制電路端子與所述輸出濾波電路的第一濾波電路端子連接，第四控制電路端子與所述輸出濾波電路的第二濾波電路端子連接並接地；所述輸出濾波電路具有兩個濾波電路端子，所述第一濾波電路端子與所述第三控制電路端子連接，所述第二濾波電路端子與所述第四控制電路端子連接並接地，所述兩個濾波電路端子用於分別連接LED負載的兩端。 An LED driving circuit comprises an alternating current (AC) input rectifying circuit, a slow lighting control circuit, and an output filtering circuit, wherein: the AC input rectifying circuit has four rectifying circuit terminals, and the first and second rectifying circuit terminals are respectively used for respectively Connecting a positive pole and a negative pole of the AC power source, the third rectifier circuit terminal is connected to the first control circuit terminal of the brightness control circuit, the fourth rectifier circuit terminal is grounded; the brightness control circuit has four control circuit terminals, The first control circuit terminal is connected to the third rectifier circuit terminal, the second control circuit terminal is connected to the reference ground, the third control circuit terminal is connected to the first filter circuit terminal of the output filter circuit, and the fourth control circuit terminal and the a second filter circuit terminal of the output filter circuit is connected and grounded; the output filter circuit has two filter circuit terminals, the first filter circuit terminal is connected to the third control circuit terminal, and the second filter circuit terminal Connected to the fourth control circuit terminal and grounded, the two filter circuit terminals are respectively connected to the LED load End.

如申請專利範圍第1項所述的LED驅動電路，其中，所述AC輸入整流電路包括保險絲、整流二極體、以及輸入濾波電容。 The LED driving circuit of claim 1, wherein the AC input rectifying circuit comprises a fuse, a rectifying diode, and an input filter capacitor.

如申請專利範圍第1項所述的LED驅動電路，其中，所述緩亮控制電路包括緩亮控制晶片、高壓啟動電阻、電流感測電阻、退磁感測及開路保護設置電阻、晶片供電電容、緩亮時間控制電容、續流二極體、以及功率電感。 The LED driving circuit of claim 1, wherein the brightness control circuit comprises a brightness control chip, a high voltage starting resistor, a current sensing resistor, a demagnetization sensing and an open circuit protection setting resistor, a chip power supply capacitor, Light-up time control capacitors, freewheeling diodes, and power inductors.

如申請專利範圍第1項所述的LED驅動電路，其中，所述輸出濾波電路包括輸出濾波電容。 The LED drive circuit of claim 1, wherein the output filter circuit comprises an output filter capacitor.

如申請專利範圍第3項所述的LED驅動電路，其中，所述緩亮控制晶片包括以下管腳：晶片內部高壓MOS管的漏極腳、晶片供電腳、退磁檢測及開路保護腳、LED電流設定腳、緩亮時間設定腳、以及晶片基準地。 The LED driving circuit of claim 3, wherein the slow-lighting control chip comprises the following pins: a drain pin of a high-voltage MOS transistor inside the chip, a chip power supply pin, a demagnetization detection and an open circuit protection pin, and an LED current. Set the foot, the fade time setting foot, and the wafer reference ground.

如申請專利範圍第3項所述的LED驅動電路，其中，所述緩亮控制晶片對所述緩亮控制電容充電，使得所述緩亮控制電容上的電壓隨時間升高，並通過感測所述緩亮控制電容上的電壓來控制所述LED驅動電路的輸出電流的大小，使得所述LED驅動電路的輸出電流的大小隨所述緩亮控制電容上的電壓的升高而增大，以實現對所述LED負載的緩亮控制。 The LED driving circuit of claim 3, wherein the brightness control chip charges the brightness control capacitor such that the voltage on the brightness control capacitor rises with time and passes the sensing The light on the control capacitor controls the input of the LED driving circuit The magnitude of the current is such that the magnitude of the output current of the LED drive circuit increases as the voltage on the dimming control capacitor increases to achieve a dimming control of the LED load.