电子信息与通信工程专业英语lesson2-2(太原理工大学版).

1、2021-7-12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 1 Chapter 2 Circuit System and Design Outline l2.1 Circuit and System l2.2 Analog and Digital Circuits Design l2.3 Radio Receiver Circuit 2021-7-12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 2.2 Analog and Digital Circuits Design Outline lAnalog circuits lDigit Circuits 2021-7

2、-12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 3 Terminology lbipolar adj.双极型 lCMOS abbr. Complementary Metal Oxide Semiconductor 互补型金属氧化物半导体 lsemiconducting material 半导体材料 lIntegrated circuits 集成电路 ltransistor n.晶体管 lDC abbr. Direct Current 直流 lAC abbr. Alternate Current 交流 ldigital adj.数字的, 计数的 lbinary adj. 具有两个的

3、;二进制的; 二变量的 lBoolean algebra 布尔代数 lpositive adj. 确实的;积极的; 肯定的;现实的;正的;阳性的 2021-7-12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 4 lnegative adj. 否定的, 否认的;反面的, 消极的反对的;负的;阴极的 lhexadecimal adj. 十六进制的 lnumber system 计数制 lCommutative Law 交换律 lAssociative Law 结合律 lDistributive Law 分配率 linverter n. 变换器; 倒相器, 倒换器; 反演器; 逆变器;

4、“非” 门 ltruth table n.真值表 lcombinational adj. 组合的 lsequential adj. 时序的 lFlip-flop n.触发器 2021-7-12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 5 lAnalog circuits are circuits dealing with signals free to vary from zero to full power supply voltage. lAnalog circuits are often referred to as linear circuits to emphasize

5、 the valid continuity of signal range forbidden in digital circuits, but this label is unfortunately misleading. Introduction Text tour 1.Analog circuits lModern circuit design is a mixed signal endeavor thanks to the availability of sophisticated process technologies that make available bipolar and

6、 CMOS, power and signal, passive and active components on the same circuit. 2021-7-12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 lJust 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 relations

7、hips between these signals are linear in the straight-line or proportional sense of the word. Many so-called linear circuits are quite nonlinear in their behavior, either by necessity of physics or by design. lThis relative mobility of electrons within a material is known as electric conductivity. C

8、onductivity is determined by the types of atoms in a material (the number of protons in each atoms nucleus, determining its chemical identity) and how the atoms are linked together with one another. 2021-7-12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 7 NPN transistors lIn fact, in the most basic and most cost effe

9、ctive analog IC processes, the chip designer has at its disposal just that a good NPN transistor. 2021-7-12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 lIn 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

10、 of the base current amplified by a factor of beta . It follows that the emitter current is one plus beta times the base current. A typical value for the amplification factor is 100. 2021-7-12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 9 lThe PNP transistor is complementary to the NPN, with the current flow enterin

11、g the emitter and exiting the collector and base, the opposite of what happens in the NPN. lSimplicity dictates that PNPs are a by-product of the NPN construction, hence they often have less beta current gain and are slower than NPNs. PNP transistors 2021-7-12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 10 MOS trans

12、istors lThe dual of Bipolar NPN and PNP transistors in CMOS technology are the P-Channel and N- Channel MOS transistors . The general function of the transistors is the same independently as their implementation but there are pros and cons to using both technologies. Generally speaking, the base, th

13、e emitter, and the collector of the bipolar transistor are analogous to the gate, source and drain of the MOS transistor, respectively. 2021-7-12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 11 l The bipolar transistors main problem, which is not present in CMOS, is their need for a base current in order to function.

14、 Such current is a net transfer loss from emitter to collector. While the base current is small in small signal operation, in power applications, where the transistor is used as a switch, the base current necessary to keep the transistor on can be very high. 2021-7-12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 12 l

15、This high base current can lead to implementations with very poor efficiency. With the popularity of portable electronics and the need to extend battery 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

16、 trans-conductance gain and better matching, leading to better differential input gain stages and better voltage references. The best performance processes 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

17、at hand. 2021-7-12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 13 2. Digit Circuits lBoolean algebra fundamentals lThe phrase “Digital electronics” is used to describe those circuit systems which primarily operate with the use of only two different voltage levels or two other binary states. Analog devices and system

18、s 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 pretend that they dont. 2021-7-12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 14 lThe NOT operation changes the value to the complement of the value. This is also re

19、ferred to as inversion or negation. lThe AND operation is a Boolean multiply and is 1 only when all values are 1. The AND is like the old string of Christmas lights. All the lights have to work to have the stringy light. l The OR operation results in a 1 if any of the values are 1. In Boolean algebr

20、a, 1+1=1 is valid. Logically the statement means if there are one or more true values, the result is true. 2021-7-12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 15 lCommutative Law: A + B = B + A lAssociative Law of Addition: A+B + C=A+(B+C) lAssociative Law of multiplication: A(BC) = (AB)C lDistributive Law: A(B+C)

21、 = AB + AC lIdentity: 1A=A, 0+A=A lComplement: A+A=1.AA=0 lDe Morgans Theorem: BABA 2021-7-12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 16 lLogic gates lIn general, a gate has one or more inputs and produces an output that is a function of the current input value(s). With each logic element there is a “truth table

22、” that explains how the unit works. And there is a symbol to represent every gate. lThe basic electronic digital operations are also NOT, AND, OR, but there are combinations of these that are also commonly used: the NAND, NOR, and EXCLUSIVE NOR. 2021-7-12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 17 lCombinational

23、 logic and sequential logic circuit lLogic circuits are classified into two types: combinational and sequential. A combinational logic is one whose outputs depend only on its current input. A combinational logic circuit may contain an arbitrary number of logic gates and inverters but no feedback loo

24、ps( a signal path of a circuit that allows the output of a gate to propagate back to the input of that same gate). 2021-7-12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 18 lWhen the input is combined with the previous state of the logic circuits, it is referred to as sequential logic. The use of the previous state i

25、s 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 example of a sequential logic circuit. 2021-7-12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 19 lIn the analysis, us

26、e 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 logic diagram. We have learned that there are five possible representations for a combinational

27、logic function: l1. truth table l2. an algebraic sum of minterms, the canonical sum l3. a minterm list using the notation l4. an algebraic product of maxterms, the canonical product l5 a maxterm list using the notation 2021-7-12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 20 lKarnaugh map, like Boolean algebra, is a

28、 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 slower. At four input variables, Boolean algebra becomes tedious. Karnaugh map

29、s 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). It simplifies a logic function by combining pairs of adjacent 1 cells into a S

30、um-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. 2021-7-12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 21 lFlip-flop is the common name given to two-state d

31、evices 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-Flops 2021-7-12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 22 2021-7-12通信与信息工程专业英语教程电子信息与通

32、 信工程专业英语 23 lIn 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. lThe 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