文獻(xiàn)翻譯--一個(gè)靈活的led驅(qū)動(dòng)汽車(chē)照明應(yīng)用集成電路設(shè)計(jì)和實(shí)驗(yàn)特征

1、<p><b>　　《畢業(yè)設(shè)計(jì)》</b></p><p><b>　　文獻(xiàn)翻譯</b></p><p>　　院　　系： 電子電氣工程學(xué)院 </p><p>　　學(xué) 號(hào)： 021309208 </p>

2、;<p>　　姓 名： 吳驍奕 </p><p>　　指導(dǎo)教師： 曾國(guó)輝 </p><p>　　完成時(shí)間： 2013/2/15

3、</p><p><b>　　文獻(xiàn)翻譯</b></p><p>　　021309208 吳驍奕</p><p>　　A Flexible LED Driver for Automotive Lighting Applications: IC Design and Experimental Characterization</p>

4、<p>　　一個(gè)靈活的LED驅(qū)動(dòng)汽車(chē)照明應(yīng)用:集成電路設(shè)計(jì)和實(shí)驗(yàn)特征</p><p>　　Abstract—This letter presents a smart driver for LEDs, particularly</p><p>　　摘要：這文章提出了一個(gè)智能驅(qū)動(dòng)發(fā)光二極管，</p><p>　　for automotive lighting

5、applications, which avoid ringing</p><p>　　尤其是用于避免振蕩和超調(diào)現(xiàn)象的汽車(chē)照明應(yīng)用上，</p><p>　　and overshoot phenomena. To this aim, advanced Soft Start and</p><p>　　為了這個(gè)目的，在芯片上集成了優(yōu)化軟啟動(dòng)和電流升降控制技術(shù)。</

6、p><p>　　Current Slope Control techniques are integrated on-chip. This letter</p><p>　　這篇文章討論了設(shè)計(jì)于集合于高電壓的互補(bǔ)金屬氧化半導(dǎo)體上的驅(qū)動(dòng)技術(shù)，</p><p>　　discusses the driver design integrating in high voltage

7、 CMOS</p><p>　　technology, the digital circuitry for programming and electronic</p><p>　　用于編程和電子控制單元連接的數(shù)字電路以及功率元件提高到10瓦特。</p><p>　　control units interfacing, and the power devices u

8、p to 10W. Experimental</p><p>　　同時(shí)也展示了不同功率等級(jí)使用的發(fā)光二極管和與不同類(lèi)型的連接時(shí)的實(shí)驗(yàn)特征。</p><p>　　characterizations with LEDs of different power levels and</p><p>　　with different types of connections

9、are showed. The smart driver</p><p>　　這個(gè)智能的驅(qū)動(dòng)適用于可調(diào)節(jié)的溫度和電壓需求。</p><p>　　sustains automotive temperature and voltage requirements; moreover</p><p>　　此外，它有很高的功率效率，它是可編程的，還可以配置用于線(xiàn)性的調(diào)節(jié)器。&

10、lt;/p><p>　　it has high power efficiency, it is programmable, and can be</p><p>　　configured to work as a linear regulator (for low current LEDs) or</p><p>　　in switch mode (for higher

11、 power LEDs).</p><p>　?。ㄓ糜谌蹼娏靼l(fā)光二極管）或轉(zhuǎn)換模式（用于高功率發(fā)光二極管）</p><p>　　IndexTerms—Automotive electronics, high voltage (HV)CMOS,</p><p>　　integrated circuit (IC), LED driver.</p><

12、p>　　關(guān)鍵詞—汽車(chē)用電子設(shè)備，高電壓互補(bǔ)金屬氧化物半導(dǎo)體，集成電路</p><p><b>　　LED驅(qū)動(dòng)</b></p><p>　　I. INTRODUCTION</p><p><b>　　1：介紹</b></p><p>　　IN the last few years LED tec

13、hnology experienced a very fast</p><p>　　在過(guò)去的幾年中，發(fā)光二極管技術(shù)在汽車(chē)照明應(yīng)用中替代普通燈泡經(jīng)歷了一個(gè)非?？焖俚倪M(jìn)步時(shí)代，</p><p>　　and important growth, superseding the bulb technology in</p><p>　　automotive lighting

14、applications [1]. To achieve the harsh requirement</p><p>　　of CO2 emission and reduce the fuel consumption,</p><p>　　car manufacturer must reduce the total power consumption. The</p><

15、;p>　　為了實(shí)現(xiàn)了嚴(yán)格的二氧化碳排放要求和降低了燃料的消耗,</p><p>　　汽車(chē)制造商必須減少總的功率消耗。</p><p>　　adoption of LEDs in place of bulbs permits to have about five</p><p>　　times less power consumption at equal ou

16、tput lighting intensity.</p><p>　　采用發(fā)光二極管代替燈泡在同等輸出功率照明強(qiáng)度下?lián)p耗將降低五倍。</p><p>　　LEDs have reached quality and reliability factors that permit</p><p>　　their use in automotive harsh envir

17、onment and in addition</p><p>　　發(fā)光二極管已達(dá)到質(zhì)量和可靠性因素,可保證他們可使用在汽車(chē)的嚴(yán)酷環(huán)境下并且他們的成本是降低的。</p><p>　　their cost is decreasing. However, LEDs are pretty difficult to</p><p>　　事實(shí)上，發(fā)光二極管是很難驅(qū)動(dòng)，因此相比較

18、普通燈泡，發(fā)光二極管驅(qū)動(dòng)要求更多的技巧和控制功能。</p><p>　　drive and therefore LED-drivers require many tricks and control</p><p>　　functions compared to bulb drivers. Moreover, automotive</p><p>　　而且，汽車(chē)應(yīng)用

19、程序需要緊湊和低成本的解決方案,靈活</p><p>　　足夠的數(shù)字電子控制單元界面，</p><p>　　applications require compact and low-cost solutions, flexible</p><p>　　enough to be interfaced to digital electronic control unit

20、s (ECU)</p><p>　　and to cope with different wiring configurations and relevant</p><p>　　同時(shí)需要應(yīng)付不同的布線(xiàn)配置和相關(guān)拓展。</p><p>　　parasitics [2]. Automotive lighting systems should be also robus

21、t</p><p>　　汽車(chē)照明系統(tǒng)也應(yīng)該對(duì)電磁干擾(EMI)和超溫、過(guò)流以及過(guò)電壓現(xiàn)象有應(yīng)變能力。</p><p>　　with respect to electromagnetic interference (EMI) and</p><p>　　to overtemperature, overcurrent, and overvoltage phenomena

22、,</p><p>　　such as those due to ringing effects generated by resonance of</p><p>　　例如那些由于激振效應(yīng)所產(chǎn)生的共振的線(xiàn)電感和連接器電容。</p><p>　　wire inductance and connector capacitance. Usually, in car en

23、vironment</p><p>　　通常,在汽車(chē)環(huán)境中，幾米長(zhǎng)電線(xiàn)使用,就會(huì)生成強(qiáng)烈振蕩。</p><p>　　few meters long wires are used, generating dumped</p><p>　　oscillations. Such oscillations and the associated overcurrent<

24、/p><p>　　and overvoltage levels reduce the LED life time and its efficiency</p><p>　　這種振蕩和與之相關(guān)的過(guò)電流和過(guò)電壓會(huì)降低發(fā)光二極管壽命及其效率。</p><p>　　[3]. To avoid or limit these effects the LED cannot be<

25、;/p><p>　　driven by a mechanical relay but a smart driver is required to</p><p>　　control the slope of the LED current during transient, keeping it</p><p>　　為了避免或限制這些影響發(fā)光二極管不能由一個(gè)機(jī)械繼電器控

26、制但智能的驅(qū)動(dòng)被要求需要在瞬態(tài)控制LED電流的斜率，以保持它在電線(xiàn)的特征頻率以下。</p><p>　　below the characteristic frequency of the wire. A compact and</p><p>　　efficient LED driver is needed, overcoming the above issues and</p>

27、;<p>　　featuring a high flexibility to face different LED power levels,</p><p>　　一個(gè)緊湊和高效的LED驅(qū)動(dòng)程序是必要的,是為了克服上述問(wèn)題和具有高靈活性，去面對(duì)不同的發(fā)光二極管功率級(jí)別，連接拓?fù)浜碗娋€(xiàn)寄生。</p><p>　　connections topology, and wiring

28、parasitics. Hereafter, Section</p><p>　　此后，在第二部分，分析了振蕩和電磁干擾在放光二極管驅(qū)動(dòng)中的影響。</p><p>　　II analyzes ringing and EMI problems in LED driving. Section</p><p>　　III presents the design of th

29、e new LED smart driver focusing on</p><p>　　第三部分介紹了一款新設(shè)計(jì)的智能發(fā)光二極管驅(qū)動(dòng)的顯著特征。</p><p>　　its distinguishing features. Section IV presents its experimental</p><p>　　第四部分介紹了發(fā)光二極管在不同功率等級(jí)下的實(shí)驗(yàn)特

30、征，從幾十毫瓦特</p><p>　　characterization with LEDs of different power levels, from tens</p><p>　　of milliwatts to several watts, used stand-alone, or connected in</p><p>　　到幾瓦特在獨(dú)立或幾個(gè)連接下的狀

31、態(tài)。</p><p>　　strings. Temperature and voltage range operating conditions are</p><p>　　溫度和電壓等級(jí)的工作條件也被測(cè)量判斷。</p><p>　　also measured. Conclusions are drawn in Section V.</p><p

32、>　　第五部分將引出結(jié)論。</p><p>　　II. RINGING AND EMI PROBLEMS IN LED DRIVING</p><p>　　二.振蕩和電磁干擾在發(fā)光二極管驅(qū)動(dòng)中的影響</p><p>　　At state-of-the-art LED, driving is implemented using lowdrop</p>

33、<p>　　out linear regulators, which are limited to LEDs of few tens</p><p>　　of milliamperes, or more power-efficient switching solutions at</p><p>　　higher current levels </p><

34、p>　　在最開(kāi)始的LED,開(kāi)車(chē)是使用低輸出線(xiàn)性穩(wěn)壓器,僅限于幾十毫安級(jí)的發(fā)光二極管,或更省電轉(zhuǎn)換解決方案用在更高的電流水平。</p><p>　　[3]–[10]. However, a compact solution integrating</p><p>　　然而,一個(gè)緊湊的集成解決方案在一個(gè)單芯片數(shù)字ECU接口,</p><p>　　on a sing

35、le chip a digital ECU interface, a low-power</p><p>　　configurable logic core, a power part able to work in linear mode</p><p>　　or switching one, as well as advanced techniques such as Soft<

36、/p><p>　　Start and Current Slope Control, has not been proposed yet in</p><p>　　一個(gè)低功耗可配置的邏輯核心,電源部分能夠工作在線(xiàn)性模式或轉(zhuǎn)換它,以及先進(jìn)的技術(shù),如軟開(kāi)始和電流升降調(diào)節(jié)，還沒(méi)有在文獻(xiàn)中被提出。</p><p>　　the literature. The main diffic

37、ulties in the design of a universal</p><p>　　設(shè)計(jì)一個(gè)足夠的靈活的發(fā)光二極管驅(qū)動(dòng)應(yīng)用在不同的接線(xiàn)配置</p><p>　　最大的難題是振蕩和電磁干擾問(wèn)題。</p><p>　　LED driver, flexible enough to be applied to different wiring</p>

38、<p>　　configurations, are the ringing and EMI issues. These problems</p><p>　　這些問(wèn)題取決于環(huán)境因素和寄生組件，這些因素很難去假設(shè)和模仿。</p><p>　　depend on environmental and parasitic components that are difficult<

39、/p><p>　　to predict and simulate.While bulbs are easily modeled as</p><p>　　而電燈泡卻很容易模仿因?yàn)樗芯€(xiàn)性的正溫度系數(shù)并且寄生成分對(duì)它的影響比較小。</p><p>　　linear positive temperature coefficient (PTC) resistors, and

40、are</p><p>　　less sensitive to parasitic components, a LED is a special diode</p><p>　　發(fā)光二極管是一種特殊的二極管，它滿(mǎn)足肖克利指數(shù)電流-電壓法。</p><p>　　and follows the Shockley exponential I–V law. A very s

41、mall</p><p>　　fluctuation on the voltage across the LED can generate a very</p><p>　　一個(gè)很小的電壓起伏通過(guò)發(fā)光二極管可能引起一個(gè)很大的電流變化影響。</p><p>　　high variation on its current affecting, as proved in

42、[3], both efficiency</p><p>　　經(jīng)證明，效率和照明設(shè)備的壽命都將被影響。</p><p>　　and life time and creating lighting disturbs. This behavior</p><p>　　如果發(fā)光二極管沒(méi)有恰當(dāng)?shù)谋或?qū)動(dòng)的話(huà)這個(gè)行為會(huì)導(dǎo)致振蕩和高強(qiáng)度的電流尖脈沖。</p><

43、;p>　　can generate ringing and high current spikes if the LED is not properly driven. By the same token, a bulb-designed driver, as</p><p>　　出于同樣的原因，燈泡的驅(qū)動(dòng)，正如10-12中說(shuō)的，不能被直接用于驅(qū)動(dòng)發(fā)光二極管。</p><p>　　s

44、hown in [10]–[12], cannot be directly used to drive efficiently</p><p>　　LEDs. This is particularly true when the LED and the driver are</p><p>　　這一點(diǎn)是完全正確的當(dāng)發(fā)光二極管和驅(qū)動(dòng)在汽車(chē)連接中被幾米的電纜分割的時(shí)候。</p>

45、<p>　　separated by a few meter cables as in automotive connections.</p><p>　　In this case, the wiring parasitics can generate ringing and EMI.</p><p>　　出于這個(gè)原因，電線(xiàn)的寄生將引起振蕩和電磁干擾。</p>&l

46、t;p>　　A comparison based on experimental measurements, between</p><p>　　一個(gè)在二瓦特的燈泡和0.1瓦特的連著很短的線(xiàn)（大概10厘米長(zhǎng)）發(fā)光二極管的比較實(shí)驗(yàn)中顯示在圖1和圖2中。</p><p>　　a 2-W bulb lamp and a 0.1-W LED turn-on transient with ve

47、ry</p><p>　　short wire (about 10 cm long) and with very long wire (about</p><p>　　3m long) is shown, respectively, in Figs. 1 and 2. A simple</p><p>　　relay is used as a switch to h

48、ighlight the different behavior</p><p>　　一個(gè)簡(jiǎn)單的繼電器被用來(lái)切換到這些負(fù)載不同的狀態(tài)。</p><p>　　of those loads. Those pictures show the necessity of using a</p><p>　　這些圖片展示了使用一個(gè)設(shè)計(jì)良好的LED驅(qū)動(dòng)從而避免寄生電路的重要性。&l

49、t;/p><p>　　well-designed driver for LEDs, to avoid unwanted effects due</p><p>　　to wiring parasitics. In fact, the behavior of the current in the</p><p>　　事實(shí)上，燈泡的電流狀態(tài)不隨著線(xiàn)的長(zhǎng)度而變化。[從圖1a圖

50、2a可以看出]</p><p>　　bulb does not change significantly with the wire length [see</p><p>　　Figs. 1(a) and 2(a)] while the transient of the current in the</p><p>　　而發(fā)光二極管的瞬間電流缺有顯著的差異。[從圖

51、1b和2b可以看出]</p><p>　　LED shows significant differences [see Figs. 1(b) and 2(b)]. To</p><p>　　overcome this issue we propose a compact solution, integrating</p><p>　　為了解決這個(gè)問(wèn)題我們計(jì)劃了一個(gè)簡(jiǎn)

52、潔的方案：</p><p>　　in 0.35-μmHVCMOStechnology the digital circuitry for driver</p><p>　　interfacing/configuration and power devices up to 10W, with</p><p>　　采用高壓CMOS技術(shù)數(shù)字電路的驅(qū)動(dòng)程序，接口/配置和功率

53、設(shè)備提高到10 瓦特</p><p>　　HV protection up to 55V. The LED driver can be interfaced to</p><p>　　同時(shí)高壓保護(hù)提高到55伏特。LED驅(qū)動(dòng)可以被顯示到數(shù)字電子控制單元，</p><p>　　digital ECU [13]–[15] and is able to cope with

54、different wiring</p><p>　　從而它可以處理各種長(zhǎng)度的電線(xiàn)配置和寄生電路。</p><p>　　configurations some meters long and their parasitics [2], and to</p><p>　　使其適應(yīng)作為線(xiàn)性穩(wěn)壓器和開(kāi)關(guān)的表現(xiàn)，取決于編程的精度。</p><p>　

55、　adapt its behavior working as linear regulator or as a switching</p><p>　　one, depending on a programmable threshold.</p><p>　　III. FLEXIBLE LED DRIVER IC</p><p>　　三. 靈活的發(fā)光二極管驅(qū)動(dòng)集成電

56、路</p><p>　　With respect to the bulb lamp driver shown in [11], [12] the</p><p>　　關(guān)于指示燈驅(qū)動(dòng)器了，智能LED驅(qū)動(dòng)必須滿(mǎn)足嚴(yán)酷的汽車(chē)環(huán)境約束。</p><p>　　smart LED driver needs to fulfill the same harsh automotive

57、 environment</p><p>　　constraints, as well as more power demanding loads,</p><p>　　同時(shí)也要滿(mǎn)足更多的功率負(fù)載需求用于串聯(lián)和并聯(lián)配置下的發(fā)光二極管。</p><p>　　as series and parallel configuration of LEDs. Low power

58、LEDs,</p><p>　　like those employed in the car dashboard, absorbing 30–50mW,</p><p>　　像那些30-50毫瓦的用于汽車(chē)儀表盤(pán)的低功率發(fā)光二極管，包括那些排列在一起的總功率到10瓦特的發(fā)光二極管或燈泡，能被提議的設(shè)計(jì)驅(qū)動(dòng)。</p><p>　　as well as arrays of

59、 power LEDs or lamps up to 10W, can be</p><p>　　driven properly by the proposed design. </p><p>　　圖1.（a）燈泡（b）發(fā)光二極管 在沒(méi)有任何電流電壓</p><p>　　控制的10厘米電纜下?tīng)顟B(tài)</p><p>　　圖2 （a）燈泡（b）發(fā)

60、光二極管 在沒(méi)有任何電流電壓控制3厘米電纜下?tīng)顟B(tài)</p><p>　　圖3. 方案一允許的負(fù)載配置,加強(qiáng)了布線(xiàn)寄生現(xiàn)象,</p><p>　　發(fā)光二極管,和串聯(lián)的電池中的開(kāi)關(guān)。</p><p>　　圖4.LED驅(qū)動(dòng)集成電路的體系結(jié)構(gòu)和詳細(xì)電路</p><p>　　The driving of LEDs has required the imp

61、lementation of specific techniques to limit the undesired effects of wiring parasitics, </p><p>　　發(fā)光二極管的驅(qū)動(dòng)要求實(shí)施特定的技術(shù)來(lái)限制布線(xiàn)寄生現(xiàn)象帶來(lái)的不良影響。</p><p>　　such as ringing andconsequent overshoots and undersh

62、oots</p><p>　　如振蕩和隨之引起的超調(diào)量和脈沖信號(hào)。</p><p>　　.In Fig. 3, the scheme of the wiring parasitic and of a possible connection between</p><p>　　the driver and the load is shown: the output p

63、in of the driver,</p><p>　　在圖三中，該計(jì)劃的布線(xiàn)寄生和可能的在驅(qū)動(dòng)和負(fù)載的連接中顯示:輸出的驅(qū)動(dòng)程序，其功能可以用一個(gè)簡(jiǎn)單的開(kāi)關(guān)描述，是連接發(fā)光二極管，并且和汽車(chē)的</p><p>　　whose functionality can be represented by a simple switch to</p><p>　　the g

64、round, is connected to a LED, in series with the car battery</p><p>　　and another switch, controlled by the user through a button or</p><p>　　電池和另外一個(gè)開(kāi)關(guān)連接，而用戶(hù)通過(guò)一個(gè)按鈕或點(diǎn)火鑰匙來(lái)控制它。</p><p>

65、　　the ignition key. The basic scheme of the flexible LED driver</p><p>　　is shown in Fig. 4, together with circuit details of the operational</p><p>　　這個(gè)靈活的發(fā)光二極管驅(qū)動(dòng)基本方案以及電路詳細(xì)的步驟和跨導(dǎo)放大器塊如圖四所示。</

66、p><p>　　transconductance amplifier (OTA) block: the architecture</p><p><b>　　這個(gè)設(shè)計(jì)基于一個(gè)</b></p><p>　　is based on a voltage regulation loop inserted inside a linear loop</p

67、><p>　　providing the current control capability.</p><p>　　插入在一個(gè)線(xiàn)性循環(huán)的電壓調(diào)節(jié)回路以提供當(dāng)前的控制能力。</p><p>　　The voltage regulationloop forces the output on a reference voltage, Vref , when </p&g

68、t;<p>　　電壓調(diào)節(jié)回路控制輸出的是參考電壓當(dāng)?shù)蛪簻y(cè)主電源開(kāi)關(guān)串聯(lián)二極管以提供反極性的容量給裝置，是開(kāi)啟了。</p><p>　　the low side main power switch (power MOS in Fig. 4), in series with</p><p>　　the Diode that provides reverse polarity ca

69、pability to the device,</p><p>　　is turn ON. The LED driver has been integrated as hard macrocell</p><p>　　LED驅(qū)動(dòng)程序已經(jīng)被集成在一個(gè)復(fù)雜的大容量的電池汽車(chē)控制單元集成電路中</p><p>　　in a complex automotive contr

70、ol unit IC, implemented in</p><p>　　Austria micro systems (AMS) 0.35 μm CMOS technology. Fig 5</p><p>　　被用在AMS0.35UM的互補(bǔ)金屬氧化物半導(dǎo)體技術(shù)中。從圖5中可以看出，</p><p>　　shows the layout and the photo

71、of the whole control unit IC,</p><p>　　布局和圖片的整個(gè)控制單元集成在電路中，使得發(fā)光二極管驅(qū)動(dòng)電子電路增強(qiáng)。</p><p>　　highlighting the LED driver circuit, and particularly the power</p><p>　　MOS and its protection d

72、iode in Fig. 4, which occupy most of</p><p>　　the LED driver area.</p><p>　　特別的在圖四中的MOS材料和二極管的保護(hù)，占絕了絕大部分的發(fā)光二極管驅(qū)動(dòng)電路。</p><p>　　By regulating the output voltage on a reference level th

73、e state</p><p>　　of the load and of the power switch can be easily detected.</p><p>　　通過(guò)調(diào)節(jié)輸出電壓在一個(gè)參考電平狀態(tài)的負(fù)載和電源開(kāi)關(guān)可以很容易地被檢測(cè)到。</p><p>　　When the LED is ON (user switch and power switch

74、in Fig. 3</p><p>　　當(dāng)發(fā)光二極管打開(kāi)，（用開(kāi)關(guān)或者圖3的電源開(kāi)關(guān)都可以使運(yùn)轉(zhuǎn)）</p><p>　　both enabled), the regulation loop is activated and the output</p><p>　　調(diào)節(jié)回路是激活的，輸出電壓是控制為參考電壓的。</p><p>　　Vo is

75、 forced on the reference voltage, Vref . If the user switch</p><p>　　同時(shí)強(qiáng)制發(fā)光二極管也關(guān)閉，如果關(guān)閉開(kāi)關(guān),因此發(fā)光二極管也關(guān)閉</p><p>　　is OFF, and hence also the LED is OFF, the output pin of the</p><p>　　dr

76、iver is pulled down even when the power switch is OFF, by</p><p>　　輸出引線(xiàn)驅(qū)動(dòng)被損壞甚至電源總開(kāi)關(guān)也關(guān)掉，意味著編的程序沒(méi)有應(yīng)變能力。</p><p>　　means of a programmable resistive path to ground. That path</p><p>　　i

77、s highly resistive to limit to very low value the current flowing</p><p>　　through the LED. Finally, if the user switch is ON but the</p><p>　　這條道路的高電阻是用來(lái)限制非常低的電流來(lái)通過(guò)發(fā)光二極管，如果用戶(hù)開(kāi)關(guān)打開(kāi)但電源開(kāi)關(guān)關(guān)閉，那么輸出電壓將

78、強(qiáng)迫輸出為電源的額定電壓。</p><p>　　power switch is forced OFF, then the output Vo is pulled up to</p><p>　　the battery voltage, Vbatt , and the LED is OFF since no noticeable</p><p>　　發(fā)光二極管也將關(guān)閉

79、直到?jīng)]有明顯的電流通過(guò)。</p><p>　　current is flowing. Summarizing, depending on the status</p><p>　　of the switch devices in Fig. 3, the output voltage Vo can be</p><p>　　pulled down to ground,

80、 or pulled up to Vbatt or forced to Vref .</p><p>　　根據(jù)不同開(kāi)關(guān)設(shè)備的狀態(tài)，如圖3所示,輸出電壓可以接地,或者強(qiáng)迫為電源的額定電壓。</p><p>　　A comparator can reveal the status of the driver and also potential</p><p>　　ov

81、ervoltage conditions by comparing the output voltage</p><p>　　to proper thresholds. Similarly overcurrent and overtemperature</p><p>　　一個(gè)比較器可以顯示驅(qū)的狀態(tài)和通過(guò)比較輸出電壓合適的閾值看出潛在的過(guò)壓條件。</p><p>　

82、　phenomena can be detected by comparing the measured current</p><p>　　and temperature values (through an on-chip temperature sensor)</p><p>　　with proper thresholds. All reference and threshold

83、levels are</p><p>　　同樣的過(guò)電流和超溫現(xiàn)象是可以探測(cè)到的測(cè)量的電流和溫度的值(通過(guò)一個(gè)芯片上的溫度傳感器)和適當(dāng)?shù)拈撝当容^。</p><p>　　internally generated by a digital-programmable band-gap unit.</p><p>　　所有的引用和閾值水平是由內(nèi)部產(chǎn)生的數(shù)字通過(guò)可編程的帶隙裝

84、置。</p><p>　　The measurements shown in this letter are obtained with a Vref</p><p>　　這篇文章中的測(cè)量值是通過(guò)額定電壓獲得，1.2伏特。</p><p>　　of 1.2V. The detected driver and load status are used by the&l

85、t;/p><p>　　internal logic as feedback signals to properly drive the power</p><p>　　MOS in Fig. 4, acting as linear regulator or ON–OFF switch,</p><p>　　檢測(cè)到的驅(qū)動(dòng)和負(fù)載狀態(tài)使用內(nèi)部邏輯作為反饋信號(hào)正確驅(qū)動(dòng)動(dòng)力在圖四

86、中的金屬氧化物半導(dǎo)體,是作為線(xiàn)性調(diào)節(jié)器或開(kāi)關(guān)</p><p>　　and implementing advanced Soft Start or Current Slope Control techniques.</p><p>　　和實(shí)施先進(jìn)的軟啟動(dòng)或電流升降控制技術(shù)</p><p>　　The working mode of the LED driver, as

87、 linear regulator or</p><p>　　ON–OFF switch, is determined by the user by proper configuring</p><p>　　the Current level Iref in Fig. 4. The MOSMA mirrors a small</p><p>　　工作模式的LED驅(qū)動(dòng)

88、,線(xiàn)性調(diào)節(jié)器或通斷開(kāi)關(guān),是由用戶(hù)通過(guò)適當(dāng)?shù)呐渲迷趫D4按圖四的電流是水平。</p><p>　　fraction of the power MOS output current and, through the HV</p><p>　　and Low-Voltage (LV) current mirrors in Fig. 4, </p><p>　　MOSMA反射

89、小部分功率從MOS輸出電流,如圖四通過(guò)高壓和低壓(LV)電流反射鏡鏡，</p><p>　　compares it to the Iref current value (generated through on-chip band-gap circuit).</p><p>　　比較其當(dāng)前值(通過(guò)芯片上的帶隙電路生成Iref)。</p><p>　　The HV P

90、MOS current mirror is connected to the output</p><p>　　voltage, which is up to 12V, while the LV PMOS current mirror</p><p>　　is connected to Vdd = 3.3V. The difference between Imir and</p>

91、;<p>　　高壓PMOS的電流反射連接到輸出電壓提高到12伏特,而低壓PMOS電流反射連接到Vdd是3伏特。</p><p>　　Iref drives the gate of MOS MB : if Imir is lower than Iref , then</p><p>　　Imir和Iref之間的在MOS驅(qū)動(dòng)上的區(qū)別是：如果Imir低于Irel，那么MB是關(guān)閉的&

92、lt;/p><p>　　MB is OFF and the power MOS, driven by the OTA in Fig. 4,</p><p>　　并且MOS的能量是由如圖四中的OTA驅(qū)動(dòng)的，通過(guò)線(xiàn)性的電流調(diào)節(jié)器。</p><p>　　acts as a linear current regulator. Otherwise, MB is ON and th

93、e</p><p>　　反之，如果MB是打開(kāi)的而電流環(huán)路控制開(kāi)關(guān)關(guān)閉，那么MOS MB將會(huì)被強(qiáng)制關(guān)閉。</p><p>　　current loop control switches to the OFF state the power MOS.</p><p>　　The MOS MB can be forced back in OFF state, and he

94、nce the</p><p>　　同時(shí)強(qiáng)制電源MOS起作用，如圖四用來(lái)進(jìn)行邏輯控制。</p><p>　　powerMOS reactived, by the control logic in Fig. 4. The control</p><p>　　logic determines the times Ton and Toff when MB is OFF (

95、i.e.,</p><p>　　這個(gè)控制邏輯決定什么時(shí)候開(kāi)什么時(shí)候關(guān)分別當(dāng)MB關(guān)掉的時(shí)候（MOS開(kāi)著）</p><p>　　power MOS is ON) or MB is ON (i.e., power MOS is OFF), respectively.</p><p>　　或者M(jìn)B開(kāi)著（MOS關(guān)閉）</p><p>　　In this

96、 case, the driver is working in ON–OFF switch</p><p>　　因此，這個(gè)驅(qū)動(dòng)工作在關(guān)或開(kāi)的模式為了滿(mǎn)足控制邏輯不停的變換開(kāi)關(guān)。</p><p>　　mode with duty cycle and frequency depending on the Ton and</p><p>　　Toff times set

97、by the control logic.</p><p>　　Summarizing, in linear regulator mode Iref is configured so</p><p>　　that the current loop control is activated only for output currents</p><p>　　of s

98、everal amperes, much higher than the operating load currents</p><p>　　總結(jié),在線(xiàn)性調(diào)節(jié)器模式Iref是如此配置的為了電流環(huán)路控制輸出電流只有安培。</p><p>　　foreseen for this LED driver (see Section IV). In linear mode,</p>&l

99、t;p>　　遠(yuǎn)高于操作負(fù)載電流的LED驅(qū)動(dòng)程序(見(jiàn)第四部分)。在線(xiàn)性莫模型中，</p><p>　　Iref acts as a protection threshold: if Imir is over Iref then MB is</p><p>　　Iref擔(dān)當(dāng)著一個(gè)保護(hù)的臨界值：當(dāng)Imir超過(guò)了Iref，那么MB會(huì)打開(kāi)，電源MOS會(huì)關(guān)閉。</p><p&

100、gt;　　switched ON and the power MOS is switched OFF.</p><p>　　In ON/OFF switching mode, Iref is configured at levels lower</p><p>　　在開(kāi)/關(guān)模式下，Iref是按從低到高電流等級(jí)配置的。</p><p>　　than normal op

101、erating currents: the power MOS is no directly</p><p>　　driven by the OTA and the combined action of the current loop</p><p>　　control and of the control logic on the MOS MB determines the</p

102、><p>　　Ton and Toff periods (and hence the switching duty cycle and</p><p>　　frequency) of the power MOS. To be noted that in switching</p><p>　　電源MOS沒(méi)有直接被OTA和聯(lián)合作用的電流環(huán)路控制。同時(shí)控制邏輯在MOS MB

103、上決定了開(kāi)或者關(guān)的周期(因此切換工作周期和頻率)。</p><p>　　mode Iref is not acting as the sole current limitation level; the</p><p>　　detection of overcurrent phenomena is carried out by the Over-</p><p>　

104、　I and Over-V detect block in Fig. 4. The described approach</p><p>　　注意,在切換模式Iref不是作為唯一的電流限制水平;檢測(cè)過(guò)流現(xiàn)象是被運(yùn)用于過(guò)壓過(guò)流檢測(cè)塊,如圖4所示。</p><p>　　allows to implement two functions in the same LED driver IC at&

105、lt;/p><p>　　minimal hardware overhead: linear regulator mode, useful for</p><p>　　所述方法可以實(shí)現(xiàn)兩個(gè)功能相同的LED驅(qū)動(dòng)集成電路在最小的硬件開(kāi)銷(xiāo):線(xiàn)性穩(wěn)壓器，用于瞬間的變化和低電流低功率LED，當(dāng)電源效率不是問(wèn)題的時(shí)候。</p><p>　　fast transient and low

106、-current/low-power LEDs, where power</p><p>　　efficiency is not an issue; switch driving mode, useful for higher</p><p>　　開(kāi)關(guān)驅(qū)動(dòng)方式，用于高電流和高功率LED，當(dāng)電源效率是關(guān)鍵問(wèn)題所以</p><p>　　current and highe

107、r power LEDs where the power efficiency is a</p><p>　　key issue and therefore a switching regulator has to be preferred</p><p>　　to a linear one.</p><p>　　線(xiàn)性的開(kāi)關(guān)穩(wěn)壓器將被成為首選。</p>

108、<p>　　The driving of a LED calls also for specific strategies to</p><p>　　avoid the ringing phenomenon on the connecting wire with</p><p>　　the consequent current overshoot. The Soft Start

109、 and Current</p><p>　　發(fā)光二極管的驅(qū)動(dòng)也要求具體策略在連接線(xiàn)上避免振蕩現(xiàn)象與隨之產(chǎn)生的電流超調(diào)。</p><p>　　Slope Control techniques, proposed by the authors in [12] for</p><p>　　bulb lamp driving (low-power dashboard in

110、dicator), have been</p><p>　　improved to maintain the same proper behavior also with arrays</p><p>　　of LEDs and high luminosity up to 10W. The design has taken</p><p>　　軟啟動(dòng)和電流斜率控制技

111、術(shù),作者在[12]中提出的燈泡驅(qū)動(dòng)(低功耗儀表板指示器),被用來(lái)保持適當(dāng)?shù)臓顟B(tài)，同時(shí)也排列二極管把光度提高到10瓦特。</p><p>　　into account the variability of parasitic capacitors and inductors,</p><p>　　設(shè)計(jì)已經(jīng)考慮到可變性的寄生電容和電感,</p><p>　　as wel