201044902 ’ . 六、發明說明： 【發明所屬之技術領威】 本發明是有關於一種驅動電路’且特別是有關於一種 發光二極體驅動器。 【先前技術】 一般而言，發光二極體(LED)驅動器係將輸入電廢轉換 為所需之輸出電壓，以驅動一或多個連接之發光二極體。 〇 然而’發光二極體驅動器通常會因某些情況(如：接收不穩 定的啟始輸入電壓）在啟動過程中發生錯誤，而無法適當地 進行啟動’因此經常造成發光二極體無法如預期地玉常運 作。 【發明内容】 本發明之一目的是在提供一種發光二極體驅動器中之 啟始迴授電路’藉以確保發光二極體驅動器能正常啟動。 ^本發明之另一目的是在提供一種發光二極體驅動器， 藉以正常穩定地操作而驅動發光二極體。 本發明之一技術樣態係關於一種發光二極體驅動器中 之啟始趣授電路，且此啟始迴授電路包含至少一個迴授次 電路、。迴授次電路包含第一電流單元、第二電流單元、第 ^電/;IL單元、第四電流單元以及鏡射單元。第一電流單元 係由接地電壓進行偏壓，以產生第一電流。第二電流單元 係用以根據第—電流產生第二電流。第三電流單元係用以 201044902 接收發光二極體迴授電壓，以產生第一電流以及第一控制 電壓。第四電流單元係用以接收第一控制電壓，以產生由 第二電流鏡射而得之第三電流，並感應出相對應第一控制 電壓之第四電流。鏡射單元係用以產生第四電流，並鏡射 第四電流以產生相對應第四電流之輸出電流，其中輸出電 流係轉換為迴授電壓，以推升發光二極體驅動器之輸出電 壓以及相對應輸出電壓之發光二極體迴授電壓。 本發明之另一技術樣態係關於一種發光二極體驅動器 中之啟始迴授電路，且此啟始迴授電路包含至少一個迴授 ® 次電路。迴授次電路包含第一 P型電晶體、第一 N型電晶 體、第二P型電晶體、第二N型電晶體、以及鏡射單元。 第一 P型電晶體具有第一控制端以及第一端，其中第一控 制端係由低位準電源電壓進行偏壓，而第一端係經由第一 電流源耦接於高位準電源電壓。第一 N型電晶體具有第二 控制端以及第二端，其中第二控制端係耦接於第一 P型電 晶體之第一端，第二端係經由第二電流源耦接於高位準電 源電壓。第二P型電晶體具有第三控制端以及第三端，其 〇 中第三控制端係用以接收發光二極體迴授電壓，第三端係 經由第一電流源耦接於高位準電源電壓。第二N型電晶體 具有第四控制端以及第四端，其中第四控制端係耦接於第 二P型電晶體之第三端，第四端係經由第二電流源所鏡射 而得之第三電流源耦接於高位準電源電壓。鏡射單元係由 第三P型電晶體以及第四P型電晶體所組成，其中第三P 型電晶體具有第五控制端以及第五端，第五控制端與第五 端耦接並耦接於第二N型電晶體之第四端，且第四P型電 201044902 晶體具有第六控制端以及第六端， 三ρ型電晶體之第五控制端，第六端二第 於低位準電源電壓並產生輸出電流，且單疋耦接 :元轉換為迴授電壓，以推升發光二極體驅動== 壓以及相對應輪出電壓之發光二極體迴授電壓。 °輪出電 本發明之又一技術樣態係關於一 器，其包含啟始職轉、操作迴 t 驅動 始迴授電路具有複數個第-端用器二 Ο Ο 迴授電壓，其中每—個發光二極體迴授電壓係由 =極體所傳送而來，且發光二極體係耦接於發光二極體 駆動器中用以輸出輸出電壓之輸出端，而啟始迴授電路係 根據上述發光二極體迴授電壓產生啟始迴授電壓。操作迴 授電路具有複數個第二端用以接收上述發光二極體迴授電 壓，且操作迴授電路係根據上述發光二極體迴授電壓產生 操作迴授電壓。多工器耦接於啟始迴授電路以及操作迴授 電路，以選擇啟始迴授電壓或操作迴授電壓。其中，當發 光二極體驅動器開始啟動時，多工器選擇啟始迴授電壓以 開始推升輸出電壓，而當該輸出電壓增加至一特定值時， 多工器則是選擇操作迴授電壓以接續推升輸出電壓。 本發明之再一技術樣態係關於一種發光二極體驅動 器，其包含啟始迴授電路、操作迴授電路、多工器、以及 補償單元。啟始迴授電路具有複數個第一端，且每一個第 一端係經由至少一發光二極體耦接於發光二極體驅動器中 用以輸出輸出電壓之輸出端，而上述第一端係用以接收複 數個發光二極體迴授電壓，且每一個發光二極體迴授電壓 201044902 係由發光二極體所傳送而來’其中啟始迴授電路 述發光二極體迴授電壓產生啟始迴授電壓。操^板辕上 具有複數個第二端，且每一個第二端係經由發光砑幾電略 接於發光二極體驅動器之輸出端，上述第二端係^槌 〜不一 係用 發光二極體迴授電壓，且每一個發光二極體迴授電隹故 發光二極體所傳送而來，其中操作迴授電路係根據饜係由 光二極體迴授電壓產生操作迴授電壓。多工器係用上逑螫 光二極體驅動器開始啟動時選擇啟始迴授電壓在發 出電壓增加至一特定值時選擇操作迴授電壓。補1賞=在輪 〇 用以比較啟始迴授電壓和參考電壓，以輸出補償二，几係 輸出電壓之初始推升動作，或是比較操作迴授電^ =用於 電壓’以輸出補償信號用於輸出電壓之接續推升動作參考 根據本發明之技術内容，應用前述發光二極體驅動 及其中啟始迴授電路，可於發光二極體驅動器開始器 時，確保發光二極體驅動器正常且良好地操作，穩^ 地驅動發光二極體。 〜疋 ◎【實施方式】 第1圖係依照本發明實施例續'示一種發光二極體(led) 驅動器的方塊示意圖。LED驅動器1 〇〇係將輸入電壓viN 轉換為輪出電壓V〇UT，藉以驅動一或多個LED 102通 道’其中每一個通道均包括一或多個串連相接之LED 102。在一實施例中’ LED驅動器1〇〇係用以驅動八個白光 LED所形成的通道，且每一個通道均包括多個串連相接之 白光lbd。此外，驅動器100可設計成一個積體電路 201044902 (ic)晶片。 LED驅動器100包括驅動單元11〇、電晶體開關、 比較器130、補償單元(如：誤差放大器14〇)、啟始迴授電 路150、操作迴授電路160以及多工器17〇。 啟始迴授電路150具有複數個第一端152，且每一個 笫一端152係相對應地耦接於一個LED 1〇2所形成的通 道。操作迴授電路160具有複數個第二端162，且每一個 第一端162亦相對應地耦接於一個LED 1〇2通道。換言之， |一個LED 102通道均耦接於上述第一端152其中一者以 0及上述第二端162其中-者’並耗接於用以輸出輸出電壓 V〇UT的輸出端。 啟始迴授電路150的第一端152係分別接收由 1〇2所傳送而來之複數個LED迴授電壓LFB，使得啟始迴 授電路150藉此產生啟始迴授電壓SFB。在此，如第i圖 戶斤示，LED迴授電壓LFB係指與啟始迴授電路15〇和操作 遒授電路160連接之第一個LED 1〇2的陰極電壓，或是與 其陰極電壓相對應的電壓。同樣地，操作迴授電路16〇的 Ο 第二端I62係分別接收由LED 102所傳送而來之LED迴授 電壓LFB，使得操作迴授電路16()藉此產生操作迴授電壓 〇FB。在一貫施例中，操作迴授電路16〇係根據所接收到 之LED迴授電壓中之最小LED迴授電壓而產生操作迴授 電壓OFB。 多工器170係耦接於啟始迴授電路15〇以及操作迴授 電路160’用以選擇啟始迴授電壓SFB或操作迴授電壓〇FB 作為補償迴授電壓FB。誤差放大器14〇係用以比較補償迴 8 201044902 授電壓FB和參考電壓VREF，以輸出補償信號VC (通常為 電壓信號）。比較器130對補償信號VC和振盪信號OS進 行比較，並產生比較信號CS。驅動單元110則接收比較信 號CS，並因此輸出脈衝驅動信號PS，藉以開啟電晶體開 關 120 〇 電晶體開關120的工作週期（duty ratio)決定輸出電壓 V0UT和輸入電壓VIN之間的比例關係。當脈衝驅動信號 PS開啟電晶體開關120時，輸入電壓VIN會對電感1〇4 進行充電，反之’當電晶體開關120未藉由脈衝驅動信號 ❹ PS開啟時’則電感104會傳送感應電流IL，因而產生輪出 電壓VOUT ’並在每一個通道中產生流經LED 1〇2的二極 體電流IOUT，而LED 102的亮度便是根據其流經之二極 體電流IOUT大小來進行變化。 在操作上，當LED驅動器1〇〇開始啟動時，多工器 會選擇啟始迴授電壓SFB作為補償迴授電壓FB，以用於 輸出電壓VOUT之初始推升動作，而當輸出電壓ν〇υτ增 加至-特定值時，多工器170會選擇操作迴授電壓卿作 為補仏迴授電壓FB’以用於輪出電壓ν〇υτ之接續推升動 作0 、 ☆具體地來說，當LED驅動器⑽開始啟動時n 授電壓FB為〇V，且夹者雷厭201044902 ′. VI. Description of the Invention: [Technical Leadership of the Invention] The present invention relates to a driving circuit' and particularly to a light emitting diode driver. [Prior Art] In general, a light-emitting diode (LED) driver converts input electrical waste into a desired output voltage to drive one or more connected light-emitting diodes. However, 'light-emitting diode drivers usually have errors in the startup process due to some conditions (such as receiving an unstable start input voltage), and cannot be properly started'. Therefore, the LEDs are often not as expected. The jade is often in operation. SUMMARY OF THE INVENTION One object of the present invention is to provide a start feedback circuit in a light-emitting diode driver to ensure that the light-emitting diode driver can be normally started. Another object of the present invention is to provide a light emitting diode driver for driving a light emitting diode by normal and stable operation. One aspect of the present invention relates to a start-up circuit in a light-emitting diode driver, and the start feedback circuit includes at least one feedback sub-circuit. The feedback sub-circuit includes a first current unit, a second current unit, a ^ electric/; IL unit, a fourth current unit, and a mirror unit. The first current unit is biased by a ground voltage to generate a first current. The second current unit is configured to generate a second current according to the first current. The third current unit is configured to receive the LED feedback voltage at 201044902 to generate a first current and a first control voltage. The fourth current unit is configured to receive the first control voltage to generate a third current that is mirrored by the second current and induce a fourth current corresponding to the first control voltage. The mirroring unit is configured to generate a fourth current and mirror the fourth current to generate an output current corresponding to the fourth current, wherein the output current is converted into a feedback voltage to boost the output voltage of the LED driver and The light-emitting diode feedback voltage corresponding to the output voltage. Another aspect of the present invention is directed to a start feedback circuit in a light emitting diode driver, and the start feedback circuit includes at least one feedback ® circuit. The feedback subcircuit includes a first P-type transistor, a first N-type transistor, a second P-type transistor, a second N-type transistor, and a mirror unit. The first P-type transistor has a first control terminal and a first terminal, wherein the first control terminal is biased by a low level supply voltage, and the first terminal is coupled to the high level supply voltage via the first current source. The first N-type transistor has a second control end and a second end, wherein the second control end is coupled to the first end of the first P-type transistor, and the second end is coupled to the high level via the second current source voltage. The second P-type transistor has a third control end and a third end, wherein the third control end is configured to receive the LED feedback voltage, and the third end is coupled to the high level power supply via the first current source Voltage. The second N-type transistor has a fourth control end and a fourth end, wherein the fourth control end is coupled to the third end of the second P-type transistor, and the fourth end is mirrored by the second current source The third current source is coupled to the high level supply voltage. The mirror unit is composed of a third P-type transistor and a fourth P-type transistor, wherein the third P-type transistor has a fifth control end and a fifth end, and the fifth control end is coupled to the fifth end and coupled Connected to the fourth end of the second N-type transistor, and the fourth P-type power 201044902 crystal has a sixth control end and a sixth end, a fifth control end of the three p-type transistor, and the sixth end is at a low level The power supply voltage generates an output current, and the single-turn coupling: the element is converted into a feedback voltage to push up the LED output voltage of the LED and the LED output voltage of the corresponding wheel-out voltage. Another technical aspect of the present invention relates to a device comprising an initial duty, an operation back to the t drive, and a feedback circuit having a plurality of first-end devices, a feedback voltage, wherein each of the The light-emitting diode feedback voltage is transmitted from the pole body, and the light-emitting diode system is coupled to the output end of the light-emitting diode actuator for outputting the output voltage, and the start feedback circuit is based on The above-mentioned light-emitting diode feedback voltage generates an initial feedback voltage. The operation feedback circuit has a plurality of second ends for receiving the light-emitting diode feedback voltage, and the operation feedback circuit generates the operation feedback voltage according to the light-emitting diode feedback voltage. The multiplexer is coupled to the start feedback circuit and the operation feedback circuit to select the start feedback voltage or the operation feedback voltage. Wherein, when the LED driver starts to start, the multiplexer selects to initiate the feedback voltage to start to push up the output voltage, and when the output voltage increases to a specific value, the multiplexer selects the operation feedback voltage. Push up the output voltage. Still another aspect of the present invention is directed to a light emitting diode driver including a start feedback circuit, an operation feedback circuit, a multiplexer, and a compensation unit. The first feedback system has a plurality of first ends, and each of the first ends is coupled to the output terminal of the LED driver for outputting an output voltage via at least one light emitting diode, and the first end system is The method is configured to receive a plurality of light-emitting diode feedback voltages, and each of the light-emitting diode feedback voltages 201044902 is transmitted by the light-emitting diodes, wherein the start-up feedback circuit generates the light-emitting diode feedback voltage generation Start feedback voltage. The operation board has a plurality of second ends, and each of the second ends is slightly connected to the output end of the LED driver via the light emitting device, and the second end system is different from the light emitting diode. The polar body returns a voltage, and each of the LEDs is relayed to the LED, and the operation feedback circuit generates an operation feedback voltage according to the feedback voltage of the photodiode. The multiplexer selects the start feedback voltage when the upper diode driver starts to start, and selects the operation feedback voltage when the output voltage increases to a specific value. Complement 1 reward = used in the rim to compare the initial feedback voltage and reference voltage to output compensation 2, the initial push-up action of several output voltages, or the comparison operation feedback power ^ = for voltage 'output compensation The signal is used for the subsequent push-up operation of the output voltage. Referring to the technical content of the present invention, the LED driving and the start-up feedback circuit thereof can be applied to ensure the LED driver when the LED driver starts. Normally and well-operated, the LED is driven steadily. 〜 ◎ [Embodiment] FIG. 1 is a block diagram showing a light-emitting diode (LED) driver according to an embodiment of the present invention. The LED driver 1 converts the input voltage viN to a turn-off voltage V〇UT, thereby driving one or more LEDs 102 channels' each of which includes one or more LEDs 102 connected in series. In one embodiment, the 'LED driver 1' is used to drive the channels formed by the eight white LEDs, and each of the channels includes a plurality of white light lbd connected in series. Further, the driver 100 can be designed as an integrated circuit 201044902 (ic) wafer. The LED driver 100 includes a driving unit 11A, a transistor switch, a comparator 130, a compensation unit (e.g., an error amplifier 14A), a start feedback circuit 150, an operation feedback circuit 160, and a multiplexer 17A. The start feedback circuit 150 has a plurality of first ends 152, and each of the ends 152 is correspondingly coupled to a channel formed by an LED 1〇2. The operation feedback circuit 160 has a plurality of second ends 162, and each of the first ends 162 is correspondingly coupled to one LED 1〇2 channel. In other words, an LED 102 channel is coupled to one of the first terminals 152 and the second terminal 162 is coupled to the output terminal for outputting the output voltage V〇UT. The first end 152 of the start feedback circuit 150 receives the plurality of LED feedback voltages LFB transmitted by the 〇2, respectively, so that the start feedback circuit 150 thereby generates the start feedback voltage SFB. Here, as shown in the figure i, the LED feedback voltage LFB refers to the cathode voltage of the first LED 1〇2 connected to the start feedback circuit 15〇 and the operation feedback circuit 160, or the cathode voltage thereof. Corresponding voltage. Similarly, the second terminal I62 of the operational feedback circuit 16A receives the LED feedback voltage LFB transmitted by the LED 102, respectively, so that the feedback circuit 16() is operated thereby generating the operational feedback voltage 〇FB. In a consistent embodiment, the operational feedback circuit 16 produces an operational feedback voltage OFB based on the minimum of the LED feedback voltages received by the LED feedback voltage. The multiplexer 170 is coupled to the start feedback circuit 15A and the operation feedback circuit 160' for selecting the start feedback voltage SFB or the operation feedback voltage FB FB as the compensation feedback voltage FB. The error amplifier 14 is used to compare and compensate the voltage FB and the reference voltage VREF to output a compensation signal VC (usually a voltage signal). The comparator 130 compares the compensation signal VC with the oscillating signal OS and produces a comparison signal CS. The driving unit 110 receives the comparison signal CS and thus outputs the pulse driving signal PS, thereby turning on the transistor switch 120. The duty ratio of the transistor switch 120 determines the proportional relationship between the output voltage VOUT and the input voltage VIN. When the pulse driving signal PS turns on the transistor switch 120, the input voltage VIN charges the inductor 1〇4, whereas when the transistor switch 120 is not turned on by the pulse driving signal ❹ PS, the inductor 104 transmits the induced current IL. Thus, the turn-off voltage VOUT' is generated and a diode current IOUT flowing through the LED 1〇2 is generated in each channel, and the brightness of the LED 102 is varied according to the magnitude of the diode current IOUT flowing therethrough. In operation, when the LED driver 1 starts to start, the multiplexer selects the start feedback voltage SFB as the compensation feedback voltage FB for the initial push-up action of the output voltage VOUT, and when the output voltage ν〇 When υτ is increased to a specific value, the multiplexer 170 selects the operation feedback voltage as the supplementary feedback voltage FB' for the successive push-up action of the turn-off voltage ν〇υτ, ☆ specifically, when When the LED driver (10) starts to start, the voltage FB is 〇V, and the player is tired.
凡夢亏電壓VREf|〇V 得補償信號VC產生，且捺屮带r 曰 11 I王且输出電壓V0UT因而自〇 v逐身 m LFB ^ a- a加至一特定值時，led迴授1 壓，藉此產生並逐漸增加。此時，啟始迴授電路 相 生啟始迴授電壓咖，並由多工器17〇進柄 201044902 擇作為補償迴授電壓FB。 值時jL 口迴授電壓SFB和參考電壓VREF增加至某一個 、，二通常知識者所謂的緩啟動（s〇ft_start)程序便已完 夕工，、啟動結束信號SEL會傳送至多工$ 170中，使得 ^ ^器170進行切換，並選擇操作迴授電路160所產生之 二壓0FB作為補償迴授電壓FB，使輸出電壓 VOUT接續的推升動作得以繼續。 ΟThe dream loss voltage VREf|〇V has to be compensated for the signal VC, and the band r 曰11 I king and the output voltage V0UT is thus added to a specific value by the v vFB ^ a- a, the led feedback 1 Press, thereby generating and gradually increasing. At this time, the start feedback circuit starts to feedback the voltage coffee, and the multiplexer 17 picks up the handle 201044902 as the compensation feedback voltage FB. When the value is, the jL port feedback voltage SFB and the reference voltage VREF are increased to a certain one, and the so-called slow start (s〇ft_start) program is completed, and the start end signal SEL is transmitted to the multiplexer $170. The controller 170 is switched, and the two-voltage 0FB generated by the operation feedback circuit 160 is selected as the compensation feedback voltage FB, so that the push-up operation of the output voltage VOUT continues. Ο
第2圖係依照本發明實施例繪示一種如第丨圖所示之 啟始迴授電路的方塊示意圖。啟始迴授電路可更包括複數 個彼此並聯相接的迴授次電路200以及與迴授次電路2〇〇 連接的電阻單元210 (如：電阻R)，其中每一個迴授次電路 2〇〇均接收一個相對應的LED迴授電壓LFB，並藉此輸出 一個輸出電流。在本實施例中，啟始迴授電路包括八個迴 授次電路200,其中第1迴授次電路200輸出輪出電流IS1， 第2迴授次電路200輸出輸出電流IS2’依此類推。然後， 電阻單元210將電流IS1、IS2、…以及IS8所組成的總電 流轉換為啟始迴授電壓SFB。 第3圖係依照本發明實施例繪示一種如第2圖所示之 迴授次電路的方塊示意圖。迴授次電路200包括第一電流 單元310、第二電流單元320、第三電流單元330、第四電 流單元340以及鏡射單元350。第一電流單元310係由低 位準電源電壓（如：接地電壓GND)進行偏壓，以產生(assert) 第一電流源II。第二電流單元320係根據第一電流源η產 生第二電流源12。第三電流單元330係接收上述led迴授 電壓LFB其中一者，以產生第一電流以及第一控制電壓 201044902 FC。第四電流單元340係接收第一控制電壓FC，以產生由 第二電流源12所鏡射而得之第三電流源13，並感應出相對 應第一控制電壓FC的第四電流14。鏡射單元350產生第 四電流14 (或稱鏡射電流），並對第四電流14進行鏡射動 作’以產生相對應第四電流14之輸出電流IS，因而產生啟 始迴授電壓SFB。在本實施例中，當LED迴授電壓LFB 增加時，第一控制電壓FC會隨之增加，使得第四電流14 和啟始迴授電壓SFB因此增加。 在本實施例中，第一電流單元310更包括第一 P型電 晶體(如：P型金屬氧化物半導體場效電晶體MP1)，其中電 晶體MP1的閘極由接地電壓GND進行偏壓，電晶體MP1 的源極經由第一電流源II麵接於高位準電源電壓VD，而 電晶體MP1的j；及極則是耦接於接地電壓GND。第二電流 單το 320更包括第一 >^型電晶體(如；N型金屬氧化物半導 體場效電晶體MN1)，其中電晶體MN1的閘極耦接於電晶 體MP1的源極，電晶體MN1的沒極經由第二電流源12輕 接於高位準電源電壓VD，而電晶體MN1的源極則是耦接 ^ 於接地電壓GND。 第二電流單元330更包括第二p型電晶體(如：p型金 屬氧化物半導體場效電晶體MP2)，其中電晶體Mp2的閘 極接收LED迴授電壓LFB，電晶體Mp2的源極經由第一 電流源II耦接於高位準電源電壓VD，而電晶體Mp2的汲 極則疋搞接於接地電壓GND。第四電流單元340更包括第 一 N型電晶體（如：N型金屬氧化物半導體場效電晶體 _2)’其中電晶體MN2的閘極耦接於電晶體.的源 11 201044902 極，電晶體MN2的汲極經由第三電流源13耦接於高位準 . 電源電壓，而電晶體MN2的源極則是柄接於接地電壓 GND。 鏡射單元350由第三P型電晶體(如：p型金屬氧化物 半導體％效電晶體MP3)以及第四p型電晶體（如·· ρ型金 屬氧化物半導體場效電晶體句所組成，其中電晶體Mp3 的閘極與汲極耦接，並耦接於電晶體MN2的汲極，電晶體 MP4的閘極耦接於電晶體Mp3的閘極，電晶體Mp4的汲 ❹極經由電阻單元210耦接於接地電壓GND，並產生與電晶 體MP3所產生之第四電流14相對應的輸出電流π，而電 晶體MP3和MP4的源極則是耦接於高位準電源電壓VD。 在一實鉍例中’電晶體MN1的大小與電晶體MN2的大小 相同。 在操作上，當LED驅動器開始啟動時，LED迴授電壓 LFB的暫態電魔為〇 v。此時，第四電流14和輸出電流岱 尚未產生。接著，當電壓LFB逐漸增加時，電壓FC隨之 ◎增加，使得電流14因而產生並逐漸增加，且電流岱亦隨 之產生並逐漸增加。如此一來，迴授電壓sfb便可相對應 ，產生而逐漸增加，藉以供選擇作為補償迴授電壓(如 第1圖所不）。接著，當迴授電壓SFB增加至某個值時，缓 啟動程序便告完成。然後，電壓OTB會取代電壓SFB，以 供選擇作為補償迴授電璧FB(如上所述）。因此，由啟始迴 授電路所產生之迴授電壓咖，可用以碟保哪驅動器在 開始啟動0^可正吊運作或啟動，而不論操作迴授電路是否 與LED驅動器的啟動程序相關。 12 201044902 由上述本發明之實施例可知，應用前述發光二極體驅 動器及其中啟始迴授電路，可於發光二極體驅動器開始啟 動時’確保發光二極體驅動器正常且良好地操作，進而穩 定地驅動發光二極體。 雖然本發明已以實施方式揭露如上，然其並非用以限 定本發明，任何熟習此技藝者，在不脫離本發明之精神和 範圍内’當可作各種之更動與潤飾，因此本發明之保護範 圍當視後附之申請專利範圍所界定者為準。 O r 【圖式簡單說明】 第1圖係依照本發明實施例繪示一種發光二極體 驅動器的方塊示意圖。 第2圖係依照本發明實施例繪示一種如第1圖所示之 啟始迴授電路的方塊示意圖。 μ 第3圖係依照本發明實施例繪示一種如第2圖所示之 迴授次電路的方塊示意圖。 〇 【主要元件符號說明】 100 :發光二極體驅動器 102 :發光二極體 104 :電感 110 :驅動單元 120 :電晶體開關 130 :比較器 13 201044902 140 :誤差放大器 150 :啟始迴授電路 152 :啟始迴授電路的第一端 160 :操作迴授電路 162 :操作迴授電路的第二端 170 :多工器 200 :迴授次電路 210 :電阻單元 〇 310 :第一電流單元 320 :第二電流單元 330 :第三電流單元 340 :第四電流單元 350 :鏡射單元 〇 14FIG. 2 is a block diagram showing a start feedback circuit as shown in FIG. The start feedback circuit may further include a plurality of feedback sub-circuits 200 connected in parallel with each other and a resistance unit 210 (eg, a resistor R) connected to the feedback sub-circuit 2〇〇, wherein each of the feedback circuits 2 Each of the 接收 receives a corresponding LED feedback voltage LFB and thereby outputs an output current. In the present embodiment, the start feedback circuit includes eight feedback sub-circuits 200, wherein the first feedback circuit 200 outputs the wheel current IS1, and the second feedback circuit 200 outputs the output current IS2' and so on. Then, the resistor unit 210 converts the total current composed of the currents IS1, IS2, ..., and IS8 into the start feedback voltage SFB. FIG. 3 is a block diagram showing a feedback sub-circuit as shown in FIG. 2 according to an embodiment of the invention. The feedback sub-circuit 200 includes a first current unit 310, a second current unit 320, a third current unit 330, a fourth current unit 340, and a mirror unit 350. The first current unit 310 is biased by a low level supply voltage (e.g., ground voltage GND) to assert the first current source II. The second current unit 320 generates a second current source 12 based on the first current source η. The third current unit 330 receives one of the LED feedback voltages LFB to generate a first current and a first control voltage 201044902 FC. The fourth current unit 340 receives the first control voltage FC to generate a third current source 13 mirrored by the second current source 12 and induces a fourth current 14 corresponding to the first control voltage FC. The mirroring unit 350 generates a fourth current 14 (or mirror current) and mirrors the fourth current 14 to generate an output current IS corresponding to the fourth current 14, thereby generating a start feedback voltage SFB. In the present embodiment, as the LED feedback voltage LFB increases, the first control voltage FC increases, so that the fourth current 14 and the start feedback voltage SFB are thus increased. In this embodiment, the first current unit 310 further includes a first P-type transistor (eg, a P-type metal oxide semiconductor field effect transistor MP1), wherein the gate of the transistor MP1 is biased by the ground voltage GND. The source of the transistor MP1 is connected to the high level power supply voltage VD via the first current source II, and the j; and the pole of the transistor MP1 are coupled to the ground voltage GND. The second current unit το 320 further includes a first type of transistor (eg, an N-type metal oxide semiconductor field effect transistor MN1), wherein the gate of the transistor MN1 is coupled to the source of the transistor MP1, and the The pole of the crystal MN1 is lightly connected to the high level power supply voltage VD via the second current source 12, and the source of the transistor MN1 is coupled to the ground voltage GND. The second current unit 330 further includes a second p-type transistor (eg, p-type metal oxide semiconductor field effect transistor MP2), wherein the gate of the transistor Mp2 receives the LED feedback voltage LFB, and the source of the transistor Mp2 is via The first current source II is coupled to the high level supply voltage VD, and the drain of the transistor Mp2 is connected to the ground voltage GND. The fourth current unit 340 further includes a first N-type transistor (eg, an N-type metal oxide semiconductor field effect transistor 2). The gate of the transistor MN2 is coupled to the source of the transistor 11. 201044902 The drain of the crystal MN2 is coupled to the high level supply voltage via the third current source 13, and the source of the transistor MN2 is connected to the ground voltage GND. The mirror unit 350 is composed of a third P-type transistor (such as a p-type metal oxide semiconductor CMOS) and a fourth p-type transistor (such as a ρ-type metal oxide semiconductor field effect transistor). The gate of the transistor Mp3 is coupled to the drain and coupled to the drain of the transistor MN2. The gate of the transistor MP4 is coupled to the gate of the transistor Mp3, and the gate of the transistor Mp4 is connected via the resistor. The unit 210 is coupled to the ground voltage GND and generates an output current π corresponding to the fourth current 14 generated by the transistor MP3, and the sources of the transistors MP3 and MP4 are coupled to the high level supply voltage VD. In a practical example, the size of the transistor MN1 is the same as that of the transistor MN2. In operation, when the LED driver starts to start, the transient electric magic of the LED feedback voltage LFB is 〇v. At this time, the fourth current 14 and the output current 岱 has not yet been generated. Then, as the voltage LFB gradually increases, the voltage FC increases ◎, so that the current 14 is generated and gradually increases, and the current 岱 is also generated and gradually increased. Thus, feedback The voltage sfb can be correspondingly generated and gradually Plus, by choice as a compensation feedback voltage (as shown in Figure 1). Then, when the feedback voltage SFB increases to a certain value, the slow start procedure is completed. Then, the voltage OTB will replace the voltage SFB to It is optional as the compensation feedback FB (as described above). Therefore, the feedback voltage generated by the start feedback circuit can be used to save the drive at the start of the 0^ can be hoisted or started. Regardless of whether the operation feedback circuit is related to the startup procedure of the LED driver. 12 201044902 It is known from the above embodiments of the present invention that the application of the LED driver and the start feedback circuit thereof can be started when the LED driver starts 'Ensure that the light-emitting diode driver operates normally and satisfactorily, and thus stably drives the light-emitting diode. Although the invention has been disclosed in the above embodiments, it is not intended to limit the invention, and anyone skilled in the art does not In the spirit and scope of the present invention, the various modifications and refinements may be made, and the scope of the present invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a light-emitting diode driver according to an embodiment of the present invention. FIG. 2 is a schematic diagram of the first embodiment shown in FIG. FIG. 3 is a block diagram showing a feedback sub-circuit as shown in FIG. 2 according to an embodiment of the present invention. 〇 [Main component symbol description] 100: LED driver 102 : Light-emitting diode 104 : Inductor 110 : Drive unit 120 : Transistor switch 130 : Comparator 13 201044902 140 : Error amplifier 150 : Start feedback circuit 152 : Start the first end of the feedback circuit 160 : Operation feedback Circuit 162: operating the second end 170 of the feedback circuit: multiplexer 200: feedback sub-circuit 210: resistor unit 〇 310: first current unit 320: second current unit 330: third current unit 340: fourth current Unit 350: Mirror unit 〇14