电子信息与通信工程专业英语lesson2-2(太原理工大学版)

1、 Chapter 2 Circuit System and Design Outline2.1 Circuit and System2.2 Analog and Digital Circuits Design2.3 Radio Receiver Circuit 8/15/20221通信与信息工程专业英语教程电子信息与通信工程专业英语2.2 Analog and Digital Circuits Design OutlineAnalog circuits Digit Circuits8/15/20222通信与信息工程专业英语教程电子信息与通信工程专业英语Terminologybipolar ad

2、j.双极型CMOS abbr. Complementary Metal Oxide Semiconductor 互补型金属氧化物半导体semiconducting material 半导体材料Integrated circuits 集成电路transistor n.晶体管DC abbr. Direct Current 直流AC abbr. Alternate Current 交流digital adj.数字的, 计数的binary adj. 具有两个的;二进制的; 二变量的Boolean algebra 布尔代数positive adj. 确实的;积极的; 肯定的;现实的;正的;阳性的8/15

3、/20223通信与信息工程专业英语教程电子信息与通信工程专业英语negative adj. 否定的, 否认的;反面的, 消极的反对的;负的;阴极的hexadecimal adj. 十六进制的number system 计数制Commutative Law 交换律Associative Law 结合律Distributive Law 分配率inverter n. 变换器; 倒相器, 倒换器; 反演器; 逆变器; “非”门truth table n.真值表combinational adj. 组合的sequential adj. 时序的Flip-flop n.触发器8/15/20224通信与信息工

4、程专业英语教程电子信息与通信工程专业英语Analog circuits are circuits dealing with signals free to vary from zero to full power supply voltage. Analog circuits are often referred to as linear circuits to emphasize the valid continuity of signal range forbidden in digital circuits, but this label is unfortunately mislead

5、ing. IntroductionText tour1.Analog circuitsModern circuit design is a mixed signal endeavor thanks to the availability of sophisticated process technologies that make available bipolar and CMOS, power and signal, passive and active components on the same circuit. 8/15/20225通信与信息工程专业英语教程电子信息与通信工程专业英语

6、Just because a voltage or current signal is allowed to vary smoothly between the extremes of zero and full power supply limits does not necessarily mean that all mathematical relationships between these signals are linear in the straight-line or proportional sense of the word. Many so-called linear

7、circuits are quite nonlinear in their behavior, either by necessity of physics or by design. This relative mobility of electrons within a material is known as electric conductivity. Conductivity is determined by the types of atoms in a material (the number of protons in each atoms nucleus, determini

8、ng its chemical identity) and how the atoms are linked together with one another. 8/15/20226通信与信息工程专业英语教程电子信息与通信工程专业英语 NPN transistorsIn fact, in the most basic and most cost effective analog IC processes, the chip designer has at its disposal just that a good NPN transistor. 8/15/20227通信与信息工程专业英语教程

9、电子信息与通信工程专业英语In this component the current flow enters the collector and base and exits the emitter. Simply stated, the transistor conducts a collector current which is a copy of the base current amplified by a factor of beta . It follows that the emitter current is one plus beta times the base curr

10、ent. A typical value for the amplification factor is 100. 8/15/20228通信与信息工程专业英语教程电子信息与通信工程专业英语The PNP transistor is complementary to the NPN, with the current flow entering the emitter and exiting the collector and base, the opposite of what happens in the NPN. Simplicity dictates that PNPs are a by

11、-product of the NPN construction, hence they often have less beta current gain and are slower than NPNs. PNP transistors8/15/20229通信与信息工程专业英语教程电子信息与通信工程专业英语MOS transistorsThe dual of Bipolar NPN and PNP transistors in CMOS technology are the P-Channel and N-Channel MOS transistors . The general func

12、tion of the transistors is the same independently as their implementation but there are pros and cons to using both technologies. Generally speaking, the base, the emitter, and the collector of the bipolar transistor are analogous to the gate, source and drain of the MOS transistor, respectively. 8/

13、15/202210通信与信息工程专业英语教程电子信息与通信工程专业英语 The bipolar transistors main problem, which is not present in CMOS, is their need for a base current in order to function. Such current is a net transfer loss from emitter to collector. While the base current is small in small signal operation, in power applicatio

14、ns, where the transistor is used as a switch, the base current necessary to keep the transistor on can be very high.8/15/202211通信与信息工程专业英语教程电子信息与通信工程专业英语This high base current can lead to implementations with very poor efficiency. With the popularity of portable electronics and the need to extend ba

15、ttery life, it is no wonder that CMOS often tends to have the upper hand over bipolar technologies. The advantage of bipolar over CMOS that it has better trans-conductance gain and better matching, leading to better differential input gain stages and better voltage references. The best performance p

16、rocesses are mixed-mode BiCMOS (Bipolar and CMOS) or BCD (Bipolar CMOS and DMOS) processes in which the designer can use the best component for the task at hand.8/15/202212通信与信息工程专业英语教程电子信息与通信工程专业英语2. Digit Circuits Boolean algebra fundamentalsThe phrase “Digital electronics” is used to describe tho

17、se circuit systems which primarily operate with the use of only two different voltage levels or two other binary states. Analog devices and systems process time-varying signals that can take on any value across a continuous range of voltage, current or other metric. The difference is that we can pre

18、tend that they dont.8/15/202213通信与信息工程专业英语教程电子信息与通信工程专业英语The NOT operation changes the value to the complement of the value. This is also referred to as inversion or negation. The AND operation is a Boolean multiply and is 1 only when all values are 1. The AND is like the old string of Christmas lig

19、hts. All the lights have to work to have the stringy light. The OR operation results in a 1 if any of the values are 1. In Boolean algebra, 1+1=1 is valid. Logically the statement means if there are one or more true values, the result is true.8/15/202214通信与信息工程专业英语教程电子信息与通信工程专业英语Commutative Law: A +

20、 B = B + AAssociative Law of Addition: A+B + C=A+(B+C)Associative Law of multiplication: A(BC) = (AB)CDistributive Law: A(B+C) = AB + ACIdentity: 1A=A, 0+A=AComplement: A+A=1.AA=0De Morgans Theorem: 8/15/202215通信与信息工程专业英语教程电子信息与通信工程专业英语Logic gatesIn general, a gate has one or more inputs and produce

21、s an output that is a function of the current input value(s). With each logic element there is a “truth table” that explains how the unit works. And there is a symbol to represent every gate.The basic electronic digital operations are also NOT, AND, OR, but there are combinations of these that are a

22、lso commonly used: the NAND, NOR, and EXCLUSIVE NOR. 8/15/202216通信与信息工程专业英语教程电子信息与通信工程专业英语Combinational logic and sequential logic circuitLogic circuits are classified into two types: combinational and sequential. A combinational logic is one whose outputs depend only on its current input. A combina

23、tional logic circuit may contain an arbitrary number of logic gates and inverters but no feedback loops( a signal path of a circuit that allows the output of a gate to propagate back to the input of that same gate). 8/15/202217通信与信息工程专业英语教程电子信息与通信工程专业英语When the input is combined with the previous st

24、ate of the logic circuits, it is referred to as sequential logic. The use of the previous state is called feedback. The outputs of sequential logic circuit depend not only on the current inputs but also on the past sequence of inputs, possibly arbitrarily far back in time. A seal-in circuit is an ex

25、ample of a sequential logic circuit. 8/15/202218通信与信息工程专业英语教程电子信息与通信工程专业英语In the analysis, use logic diagram and proceed to a formal description of the function performed by that circuit, such as a truth table or a logic expression. In the synthesis, from a formal description and proceeding to a log

26、ic diagram. We have learned that there are five possible representations for a combinational logic function:1. truth table2. an algebraic sum of minterms, the canonical sum3. a minterm list using the notation4. an algebraic product of maxterms, the canonical product5 a maxterm list using the notatio

27、n8/15/202219通信与信息工程专业英语教程电子信息与通信工程专业英语Karnaugh map, like Boolean algebra, is a simplification tool applicable to digital logic. Boolean simplification is actually faster than the Karnaugh map for a task involving two or fewer Boolean variables. It is still quite usable at three variables, but a bit

28、slower. At four input variables, Boolean algebra becomes tedious. Karnaugh maps are both faster and easier. Karnaugh maps work well for up to six input variables, are usable for up to eight variables. For more than six to eight variables, simplification should be by CAD (computer automated design).

29、It simplifies a logic function by combining pairs of adjacent 1 cells into a Sum-Of-Products terms that covers all of the 1 cells. Form groups of 1s to cover all 0s. The Product-Of-Sums simplified result is built. By the definition of minimal cost solution, the SOP solution is simpler.8/15/202220通信与

30、信息工程专业英语教程电子信息与通信工程专业英语Flip-flop is the common name given to two-state devices which offer basic memory for sequential logic operations. Flip-flops are heavily used for digital data storage and transfer and are commonly used in banks called registers for the storage of binary numerical data. Flip-Fl

31、ops8/15/202221通信与信息工程专业英语教程电子信息与通信工程专业英语8/15/202222通信与信息工程专业英语教程电子信息与通信工程专业英语In an S-R latch, activation of the S input sets the circuit, while activation of the R input resets the circuit. If both S and R inputs are activated simultaneously, the circuit will be in an invalid condition.The J-K flip-flop is a modified version of an S-R flip-flop with no “invalid” or “illegal” output state. So a J-K flip-flop is nothing more than an S-R flip-flop with a