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1、TEXT TOUR,How Does a Logic Gate in a Microchip Work?,A gate seems like a device that must swing open and closed,yet microchips are etched onto silicon wafers that have no moving parts.So how can the gate open and close?,1-2 How does a logic gate in a microchip work?（片子上的逻辑门如何工作的）,1、Larry Wissel,ASIC
2、 Applications Engineer at IBM Microelectronics,replies:2、Tak Ning of the IBM T.J.Watson Research Center adds some complementary details:3、Whats a MOSFET?,In a computer,a gate controls the flow of electric current through a circuit.The gate consists of transistors.在电脑中，门控制着通过电路的电流。门电路由晶体管组成.,1、Larry
3、Wissel,ASIC Applications Engineer at IBM Microelectronics,replies:,The transistors are selected by the chip designer from two basic types:PMOS and NMOS transistorsthat are found in the ubiquitous CMOS(complementary metal-oxide semiconductor)technology.而这些晶体管是由芯片的设计者从广泛使用的CMOS（互补金属氧化物半导体）技术中出现的两种基本类型
4、的晶体管（PMOS晶体管和NMOS晶体管）选择确定的。,The current that flows through a gate establishes a voltage at a particular point in the circuit.This voltage represents a single bit of information.The voltage may either be high(representing the value 1)or low(representing the value 0).通过一个门的电流在电路的特定的点确立一个电压.这个电压代表一比特的信
5、息，该电压可以为高电平（1），也可以为低电平（0）。,How to establish a 1 or a 0 on a circuit:To establish a 1 on a circuit:The current flow is steered to the circuit(controlled)by turning on a PMOS transistor connected between the circuit and the positive supply voltage.电流被驱动送到一个电路上，是通过“接通”一个连接该电路点和正向电源电压的PMOS管来控制的.,For the
6、 very brief interval that is required for a logic gate to switch,current will flow through a PMOS transistor from the positive power supply to the circuit.对于逻辑门切换状态所需的非常短的时间段，电流将从电源正极流经PMOS管到达该电路点。,To establish a 0 on a circuit:The current flow is steered away from the circuit through a different ki
7、nd of transistor(NMOS)connected between the circuit and the negative supply voltage,or electrical ground.电路上的“0”值的确立是通过另一种连接该电路点和负极电压或接地的晶体管（NMOS）来实现的。,Current will flow through the NMOS transistor for a very brief interval.But for the NMOS the current is between the circuit and the negative supply.
8、在一个很短暂的时间间隔里，电流经过NMOS晶体管，但对于NMOS来说，电流是在该电路点和电源负极间流动的。,In either case,the current flow results in a change in the circuit voltage that represents a bit of information.So,when a gate is controlling current flow,it is actually controlling the flow of information.这两种情况中，电流流动导致电路上电压的改变都代表一比特（1bit）的信息。因此，
9、当“门”控制电流流动时，实际也控制了信息的变化或流动。,The analogy between the farm and the computer chip is different.the flow the gate itselfthe most important difference is the means of controlling the flow(控制流动的方式不一样).,In a computer chip,the control mechanism is the voltage on the control terminal of a transistor.This vol
10、tage turns on a transistor by changing its characteristics from that of an open circuit(the off position)to one that can conduct a small current.在电脑芯片中，控制机制是晶体管的控制电压。这个电压打开一个晶体管，是通过改变管子的导通状态，即从开路状态（即“关”位置）到另一种可通过小电流的状态。,This control voltage,in turn,is already available within the chip as a voltage a
11、t a point on another circuit.And,being a voltage on a circuit,this control mechanism represents a different bit of information.然后，这个控制电压作为芯片内部另一个电路节点上的电压便可得到。因此，电路上的一个电压值，就代表着这种控制机制下不同状态的1比特的信息。,2、Tak Ning of the IBM T.J.Watson Research Center adds some complementary details:A logic gate in a microc
12、hip is made up of a specific arrangement of transistors.For modem microchips,the transistors are of the kind called metal-oxide-semiconductor field-effect transistor(MOSFET).集成电路块中的逻辑门是由特定布局的晶体管组成的。,A MOSFET has three components or regions:a source region,a drain region and a channel region.The thre
13、e regions are arranged horizontally adjacent to one another,with the channel region in the middle.一个MOSFET管有三个极区：源极、漏极和栅极，这三个极彼此水平相邻，沟道（漏级）居中。,In a logic gate arrangement,each of the MOSFETs works like a switch.The switch is closed,or the MOSFET is turned on,if electric current can flow readily from
14、 the source to the drain.The switch is open,or the MOSFET is turned off,if electric current cannot flow from the source to the drain.,在逻辑门电路的排列中，每个MOSFET管就像一个开关一样.如果电流可以容易地从源极流向漏极，则开关处于闭合状态，或MOSFET管处于开启状态如果电流不能从源极流向漏极，则开关处于断开状态，或MOSFET管处于关闭状态。,The source and drain regions of a MOSFET are fabricated
15、to be full of electrons which are ready to carry current.The channel region,on the other hand,is designed to be empty of electrons under normal condition,blocking the movement of current.源极和漏极由充满了能传导电流的电子构成.而另一方面，正常情况下的沟道区没有电子，可阻止电流通过。,Hence,under normal condition,the MOSFET is off(or open)and no cu
16、rrent can flow from the source to the drain 因此在正常状态下，MOSFET管是断开(即的“开路”状态)，没有电流从源极流向漏极。,If a positive voltage is applied to the gate,negative charges,will be attracted toward the gate.are collected in the channel region of the MOSFET.The larger the gate voltage,the larger is the concentration of elec
17、trons in the channel region.假如门上加一个正向电压（加在沟道上），于是带负电的电子会吸向该门，这些电子在MOSFET管的沟道区聚集，门上电压越大，在沟道中聚集的电子就越多。,The substantial concentration of electrons in the channel provides a path by which the electrons can move easily from the source to the drain.When that happens,the MOSFET is on(or closed)and current
18、can flow from the source to the drain freely.在沟道中大量电子聚集提供了一条电子很容易地从源极流向漏极的通道，在这些发生时，MOSFET管是接通的（或“关”状态），电流能自由地从源极流到漏极。,In summary,a MOSFET in a microchip is turned on by applying a voltage to the gate to attract electrons to the channel region,and turned off by applying a voltage to the gate to repe
19、l electrons away from the channel region.总之，微芯片中的MOSFET管是通过给栅极提供一个门电压吸引电荷到沟道区而接通电路的，通过给栅极加载一个电压阻止沟道中的电荷来断开电路的。,3、Whats a MOSFET?metal-oxide-semiconductor field-effect transistor.Its a kind of transistor that clips gradually when overdriven,as most tubes do.,There are basically three kinds of transis
20、tor that are used to amplify audio:a bipolar transistor:NPN PNP the field-effect transistor(FET).MOSFET,WORDS,CMOS(complementary metal-oxide semiconductor)互补金属氧化物半导体involved invlvda.繁杂的，受牵扯的MOSFET(metal-oxide-semiconductor field-effect transistor)金属氧化物半导体场效应晶体管reminisce reminisv.缅怀往事，话旧steer stiv.掌舵
21、，操纵，驾驶ubiquitous ju:bikwitsa.无处不在的wafer weifn.晶片，圆片,Phrases,solid-state adjective 固态物理学的【物】固态的;固体的 Solid-state electronic equipment is made using transistors or silicon chips,instead of valves or other mechanical parts.solidstate physics 固态物理,Depend on and be dependent on,depend 是不及物动词，没有被动形式。词组depe
22、nd on 意思是依赖，取决于，相信，依而定。例句：That depends.视情形而定。It all depends on how you tackle the problem.那要看你如何应付这问题而定。Can I depend on you?我可以信任你吗？I havent a car,I have to depend on the buses.我没有汽车，只能靠公共汽车。depend on 和 be dependent on 意思一样，都有依赖，由决定，取决于的意思。,by no means,by no means;not by any(manner of)means not at all 决不；一点也不 By all means 无论如何，一定By means of 用，借助于,summary,
