電子專業(yè)畢業(yè)設計（論文）外文文獻及翻譯-全雙橋電機保護驅動器（a3976）

1、<p><b>　　中文2723字</b></p><p><b>　　外文文獻</b></p><p><b>　?。ㄒ唬┰?lt;/b></p><p>　　DUAL FULL BRIDGE PROTECTED MOTOR DRIVER（A3976）</p><p>

2、　　The A3976 is designed to drive both windings of a bipolar stepper motor or bidirectionally control two DC Motors. Both H-Bridges are capable of continuous output currents of up to +/- 500 mA and operating voltages to 3

3、0V. Free wheeling, substrate isolated diodes are included for output transient suppression when switching motors or other inductive loads. For each bridge the PHASE input controls load current polarity by selecting the a

4、ppropriate source and sink driver pair. The ENABLE input, when</p><p><b>　　FEATURES</b></p><p>　?。?） 30 V , ±500 mA Continuous Output Rating</p><p>　?。?）35V Load Du

5、mp Survival</p><p>　?。?）Output Short Circuit Protection</p><p>　?。?）Coded Fault Diagnostic Outputs</p><p>　　（5）Low Current Standby Mode</p><p>　?。?）Open Load Monitor<

6、;/p><p>　?。?） Low Current Standby Mode</p><p>　?。?） VBB Over Voltage Shutdown</p><p>　?。?） Internal Thermal Shutdown Circuitry</p><p>　?。?0） Internal Low Parasitic Free Wh

7、eeling Diodes</p><p>　?。?1） Crossover Current Protection</p><p>　　ABSOLUTE MAXIMUM RATINGS</p><p>　　at TA = +25°C</p><p>　　Operating Supply Voltage, VBB ..........

8、.......... 30 V</p><p>　　Non-Operating Supply Voltage..................... 35 V</p><p>　　Output Current, IOUT ............................±500 mA*</p><p>　　Logic Supply Voltage

9、, VCC.......................... 7.0 V</p><p>　　Fault Output Voltage ................................... 7.0 V</p><p>　　Logic Input Voltage Range,</p><p>　　VIN.......................

10、... -0.3 V to VCC + 0.3 V</p><p>　　Package Power Dissipation (TA = +25°C), PD</p><p>　　A3976KLB..................................2.2 W</p><p>　　A3976KB ........................

11、............2.9 W</p><p>　　Operating Temperature Range,</p><p>　　TA ..............................-40°C to +125°C</p><p>　　Junction Temperature, TJ .......................

12、..+150°C</p><p>　　Storage Temperature Range,</p><p>　　TS...............................-55°C to +150°C</p><p>　　* Output current rating may be limited by duty cycle,&

13、lt;/p><p>　　ambient temperature, and heat sinking. Under any set of</p><p>　　conditions, do not exceed the specified current rating or a</p><p>　　junction temperature of 150°C.<

14、;/p><p>　　Input Logic</p><p>　　Fault Logic</p><p>　　APPLICATION NOTES</p><p>　　Open Lead Protection. During normal PWM operation diagnostic circuitry will look for a minim

15、um source current level after a bridge is signalled on. Additionally, the diode flyback is monitored on the proper output. The logic will signal a fault and disable the outputs if it determines that the current is below

16、the minimum level AND no flyback is occurring. If the inductive load is too large, the current would take too long to reach the minimal level and a false open load would be reported. It is</p><p>　　Short Cir

17、cuit Protection. Internal sense resistors in series with VBB and ground will trip the fault circuitry if greater than 1.1A is detected. To prevent false overcurrent events due to reverse recovery spikes of the clamp diod

18、es, the current monitor is blanked for 5us after a high side is signalled to turn on. If an additional input command follows after the initial fault, the selected pair of drivers will pulse on for the 5us blanking durati

19、on. The short circuit fault will remember the input</p><p>　　Thermal Protection. Circuitry turns OFF all drivers when the junction temperature reaches 170°C typically. It is intended only to protect the

20、 device from failures due to excessive junction temperatures and has a hysteresis of approximately 15°C.</p><p>　　Layout. The printed wiring board should use a heavy ground plane. For optimum electrical

21、 and thermal performance, the driver should be soldered directly onto the board. The load supply pin, VBB, should be decoupled with an electrolytic capacitor (> 47 μF is recommended) placed as close to the device as p

22、ossible</p><p>　　Enengy or Solar Enegry</p><p>　　Energy means the power which does work and drives machines. All living things (including humans) rely on the sun as a source of energy. Coal, pet

23、roleum, and natural gas are energy sources available today because organisms in the past captured sunlight energy and stored it in the complex organic molecules that made up their bodies, which were then compressed and c

24、oncentrated. With the development of society, a large of energy sources have been used,such as coal, petroleum, natural gas, geothermal</p><p>　　At present, most of the energy consumed by humans is produced

25、from fossil fuels. The greatest recoverable fossil is in the form of coal and lignite. Although world coal resources are enomous and potentially can fill energy needs for a century or two, their utilization is limited by

26、 environmental disruption from mining and emissions of carbon dioxide and sulfur dioxide. These would become intolerable long before coal resources were exhausted. Only a small percentage of coal and lignite has been u&l

27、t;/p><p>　　Since first commercial oil well in 1859, somewhat more than 100 million barrels of oil have been produced in the United States, most of it in recent years. In 1990 world petroleum consumption was at

28、a rate of about 65 million barrels per day. Projected use of petroleum and natural gas indicates rapid depletion. Alaskan oil can help the petroleum supply only temporarily. Peak world petroleum resources production will

29、 be reached within a few years. </p><p>　　Since the first "energy crisis" of 1973-1974, some concrete actions have even taken place. However, the several-fold increase in crude oil prices since 197

30、3 has extacted a toll. In the U.S. and other industrialized nations, the economy has been plagued by inflation, recession, unemployment, and obsolescence of industrial equipment. The economies of some petroleum-deficient

31、 developing countries have been devastated by energy prices. </p><p>　　Energy crisis was accompanied by worldwide shortages of some foods and minerals, followed in some cases by surpluses, such as the surplu

32、s wheat resulting from increased planting and a copper surplus resulting from the efforts of copper-producing nations to acpuire foreign currency by copper export. </p><p>　　As known to all,the availability

33、and cost of energy has become dominant factors in society today. Obviously, solving the "energy crisis" makes good sense. Many schemes has been proposed for conserving present energy resources and for developin

34、g new ones. It is always possible to use less energy in any process. Therefore, energy engineer is created and developed. The first goal of energy engineer is to determine the methods by which energy utilization is reduc

35、ed but the output remains the same, o</p><p>　　Conventional engineering techniques are used to evaluated the mechanisms of energy use. Economic considerations are of equal importance and life cycle cost and

36、saving techniques are used to determine cost-effective measures. The evaluation focuses on those uses which are significant in the overall picture and attempts to determine those technical measures that can reduce usage

37、and save money. </p><p>　　Meanwhile, looking for ideal energy sources is also very important to solve energy crisis. The recipe for an ideal energy source calls for one that is unlimited in supply, widely av

38、ailable, and inexpensive; it should not add to the earth's total heat burden or produce chemical air and water pollutants. Solar energy fulfills all of these criteria. Solar energy does not add excess heat to that wh

39、ich must be radiated from the earth. On a global basis, utilization of only a small fraction of solar e</p><p>　　Solar energy is unlimited in supply, but its exploitation and utilization are limited owing to

40、 the limitation of technology and conditions. Solar energy utilization needs an enormous amount of land, and there are economic and environmental problems related to the use of even a fraction of this amount of land for

41、solar energy collection. Certainly, many residents of Arizona would not be pleased at having so much of the state devoted to solar collectors, and some environmental groups would protest</p><p>　　Solar power

42、 cells for the direct conversion of sunlight to electricity have been developed and are widely used for energy in space vehicles. With present technology, however, they remain too expensive for large-scale generation of

43、electricity. Therefore, most schemes for the utilization of solar power depend upon the collection of thermal energy, followed by conversion to electrical energy. The simplest such approach involves focusing sunlight on

44、a steam-generating bioler. Parabolic refkectors c</p><p><b>　?。ǘ┓g</b></p><p>　　全雙橋電機保護驅動器（A3976）</p><p>　　A3759是一種用來驅動雙極性步進電機雙繞組的單片集成電路，也可以用來雙向控制兩臺電動機。雙H橋能夠連續(xù)輸出±～

45、500mA的電流和30V的運行電壓。當開關電動機或者是其他感性負載時，襯底隔離的續(xù)流二極管可以起到輸出抑制的作用。對于每一個H橋，相位（PHASE）輸入端能通過選擇合適的電源和驅動器控制電流的極性，使能（ENABLE）輸入置成高電平時，可以使各自的H橋導通。當2個ENABLE引腳都被置成低電平時，芯片進入睡眠狀態(tài)，消耗不到100微安的電流。</p><p>　　A3976附加了許多保護功能，以確保電路在苛刻得環(huán)境

46、下工作，并且為了應用于汽車而進行了特別設計。保護電路能夠檢測到負載開路或者短路、電動機短路接地或短路接電源、功率電源VBB過電壓、邏輯電源VCC欠電壓、過熱關斷等。如果檢測到這些，輸入就會被禁止，故障信息通過診斷引腳即為FAULT1和FAULT2輸出。</p><p><b>　　芯片特點：</b></p><p>　?。?）具有30V，±500mA的連續(xù)輸

47、出能力</p><p>　?。?）具有35V清除殘存功能</p><p>　　（3）具有輸出短路保護</p><p>　?。?）可輸出編碼的故障診斷信號</p><p>　?。?）內部含有開路負載監(jiān)視器</p><p>　?。?）設有弱電流待命模式</p><p>　?。?）設有負載開路監(jiān)視器&

48、lt;/p><p>　?。?）具有功率電路電源VBB過電壓關斷功能</p><p>　　（9）內部含有熱關斷電路</p><p>　?。?0）內部含有低寄生續(xù)流二極管</p><p>　　（11）具備交叉式電流保護功能</p><p>　　A3976工作環(huán)境與性能參數為：</p><p>　?。?）

49、運行供電電壓VBB：30V</p><p>　?。?）輸出電流IOUT：±500mA</p><p>　?。?）邏輯供電電壓VCC：7.0V</p><p>　?。?）故障輸出電壓：7.0V</p><p>　?。?）邏輯輸入電壓范圍VIN：-0.3V～VCC+0.3V</p><p>　?。?）芯片功耗（T

50、A+25°C）PD：2.2W（A3976KLB），2.9W（A3976KB）</p><p>　　（7）工作溫度范圍TA：-44～125°C</p><p>　　（8）存儲溫度范圍TS：-55～15.°C</p><p><b>　　輸入邏輯關系</b></p><p>　　故障輸出信號與故

51、障種類的關系</p><p><b>　　使用須知：</b></p><p>　　開環(huán)保護電路：在正常情況下，當一個橋路被保護后，PMW操作診斷電路將會監(jiān)視最低電源電流。同時，掃描作用的二極管將會監(jiān)視輸出信號是否正確。如果輸出低于最小值或監(jiān)視電路出現故障，邏輯電路將會輸出錯誤信號并且停止輸出。如果感性負載過大，電流將會持續(xù)很長時間以接近最小值，并且將會報告一個錯誤的開

52、環(huán)信息。因此感性負載應小于38mH。</p><p>　　短路保護電路：當檢測到大于1.1A的電流后，VBB與地的地的檢測電阻將會訪問故障電路。為防止由于鉗位二極管的峰值反轉而產生過電流事件的發(fā)生，當前監(jiān)視器在高位端被通知開啟后自動暫停5微秒。當出現一個故障引起的中斷后，其對應的驅動部分將會停止5微秒。在正常操作被允許執(zhí)行之前，短路故障將會存儲故障發(fā)生的輸入狀態(tài)并且會等待故障被移除的特殊邏輯信號的到達。</

53、p><p>　　熱保護電路：當溫度達到170°C時，保護電路將會關閉所有的驅動器。這是為了防止由于溫度過高而產生故障，溫度范圍為15°C左右。</p><p>　　電路板中部件的布局：為了達到最佳電特性與溫度特性，驅動部件應該緊貼著印刷板進行焊接。負載電源引腳VBB應接一個電解電容（建議大于47μF）作為緩沖裝置，并且應該盡量接近驅動部件進行焊接。</p>&

54、lt;p><b>　　能源與太陽能</b></p><p>　　能源就是能夠用于工作和驅動機器的能量。所有的生物（包括人類）都是依靠陽光作為能量的來源。煤、石油和天然氣都是可以利用的能源，這些能源都是過去的生物體在太陽光能源的作用下生成復雜的存儲這些能源有機分子結構經過長時間的壓縮集中后生成的。大量的能源已經被使用，如煤炭、石油、天然氣、地熱資源、核聚變能源、核裂變能源、太陽能和氫氣等

55、。然而，在這種情況下，由于許多能夠產生能量的資源是不可再生的，大量的使用這些能源可能會引起能源危機。</p><p>　　目前，人類的能源消耗主要體現在燃料資源的消耗上?，F在的固體狀能源主要是煤炭，目前已知的加上潛藏的煤炭儲量最多可使用一到兩個世紀，而且煤炭的開采和使用會破壞環(huán)境并且產生大量的二氧化碳與二氧化硫。當煤炭資源用盡前這些影響將會越來越惡劣。煤炭在能源的利用方面的比例已經越來越低，而石油和天然氣正在被大

56、量的使用著。作為能源，石油比煤炭有更大的優(yōu)勢。其開采地比煤炭更為集中因此對環(huán)境的破壞要少，其燃燒產生的污染物要比煤炭少，而且石油可以很容易的通過管道進行運輸。同時這些優(yōu)勢使石油成為理想的汽車燃料。</p><p>　　自從1859年第一個商業(yè)油田的建成以來，美國已經生產了超過100萬桶石油，其中大部分是在最近幾年生產的。1990年全世界約消耗了65萬桶石油。石油與天然氣資源在迅速的消耗著，阿拉斯加出產的石油只能暫

57、時緩解石油的供應危機。世界石油的生產將在幾年之內達到最高值。</p><p>　　自從1973～1974年的第一次“能源危機”以來，已經出現了一些具體的措施。然而，自1973年以來，原油的價格已經提高了若干倍。美國和其他工業(yè)化國家一直受到通貨膨脹、經濟衰退、大批的失業(yè)和工業(yè)設備的過時的困擾。一些石油不足的發(fā)展中國家由于能源價格的關系其經濟已經遭到破壞。</p><p>　　在能源危機的同時

58、，世界范圍內還有一些食品和礦產資源的短缺，其次一些物品的生產則出現過剩，如小麥和銅的生產過剩，一些銅生產國將銅以銅幣的形式出口。</p><p>　　眾所周知，能源的供應和成本已經成為當今社會的一個主要的話題。很顯然，解決“能源危機”是非常有意義的。目前已經有許多節(jié)約能源和發(fā)展新能源的計劃被提出來。在任何領域節(jié)約能源都是可行的。因而，能源工程師這個職業(yè)產生并迅速發(fā)展起來。能源工程師的第一個提議是想辦法減少能源的消

59、耗同時保證產量不變甚至有所提高，第二個提議是尋找降低能源成本的方法。</p><p>　　傳統(tǒng)的工程技術被用來評估能源利用的技術。周期成本與用于節(jié)省資金的方法與經濟利益同等重要。評價的重點是整個大局中的重要性和減少浪費和使用的資金的方法。</p><p>　　同時，尋找更為理想的能源是非常重要的。解決能源危機的一種理想的能源的要求應該是無限的供應、能夠被廣泛的使用、價格低廉、而且其使用后不

60、會添加地球的總熱量的負擔或者不會產生化學空氣和水污染物的排放。太陽能滿足這些標準，其產生的多余的熱量會從地球輻射出去。而且利用照射到地球的一小部分太陽能就能夠提供地球所需的能源。</p><p>　　太陽能的供應是無限的，但是由于技術和條件的限制，其開發(fā)和利用是有限的。太陽能的利用需要大量的土地，還有經濟和環(huán)境方面的要求，而且這一部分土地上太陽能的收集也只能達到一小部分。當然，亞利桑那州的許多居民渴不喜歡國家大力

61、發(fā)展太陽能的收集，而且一些環(huán)保組織也因為太陽能的收集對響尾蛇的生活習性等產生的影響而抗議太陽能收集裝置的實行。</p><p>　　太陽能電池能夠將太陽能直接轉化為電能，而且已經廣泛應用于空間飛行器能源的提供。然而，以目前的技術水平如果應用于大規(guī)模發(fā)電其代價于昂貴。因此，目前大多數太陽能發(fā)電方式仍舊是首先將太陽能轉化為熱能，然后再將熱能轉化為電能。這種方式目前最簡單的設計是蒸汽發(fā)電裝置，收集到的太陽能通過管道中的