一百条模拟设计经验

kjspace

希望有能力的牛人把它翻译后贴出来
1/ Capacitors and resistors have parasitic inductance, about 0.4nH for surface mount and 4nH for a leaded component.  
2/ If you don"t want a high bandwidth transistor to oscillate place lossy components in at least 2 of the 3 leads. Ferrite beads work well.  
3/ When taking DC measurements in a circuit and they don"t make sense, suspect that something is oscillating.  
4/ Opamps will often oscillate when driving capacitive loads.  
5/ The base-emitter voltage Vbe of a small signal transistor is about 0.65v and drops about 2mV/deg C. Vbe goes down with increasing temp.
6/ Multiply 0.13nV by the square root of the ohmic value of a resistor to find the noise in a 1Hz bandwidth. Then multiply by the square root of the BW in Hz gives the total noise voltage.  
7/ Johnson noise current goes down with a increase in resistance.
8/ The impedance looking into the emitter of a transistor at room temp is 26Ohm/Ie in mA  
9/ All amplifiers are differential in that they are referenced to ground somewhere.  
10/ Typical metal film resistor has a temp coef of about 100 ppm/deg C  
11/ The input noise voltage of a quiet op amp is 1nv/sqrt(Hz) but there are plenty available with 20nV/sqrt(Hz). Op amps with bipolar front-ends have lower voltage noise and higher current noise than those with FET front-ends  
12/ Using an LC circuit as a power supply filter can actually multiply the power supply noise at the filter"s resonant frequency. Use inductor with low Q to overcome this.  
13/ Use comparators for comparing and op amps for amplifying and don"t even think of mixing the two.  
14/ Ceramic caps with any other dielectric other than NPO should only be used for bypass applications.  
15/ An N-channel enhancement-mode FET needs +ve voltage on the gate-source to conduct form drain-source.  
16/ Small signal JFETS work very well as low-leakage diodes by connecting drain & source together in log current-to-voltage converters and low leakage input protection. Small signal bipolars with b-c tied together will also make nice low-leakage diodes.  
17/ With low pass filter use Bessel for least amount of overshoot in the time domain, and Cauer (or elliptic) for fastest rolloff in the freq domain.  
18/ dB is always 10 times the log of the ratio of 2 powers.  
19/ At low frequencies, the current in the collector of a transistor is in phase with the applied current at the base. At high frequencies the current at the collector lags by 90deg. You must appreciate this simple fact to understand high frequency oscillators.  
20/ The most common glass-epoxy PCB material (FR4) has a dielectric constant of about 4.3 To make a trace with a characteristic impedance of 100 Ohm, use a trace thickness of about 0.4 times the thickness of the board with a ground plane on the opposite side. For a 50Ohm trace make it 2 times the thickness.  
21/ If you need a programmable dynamic current source, find out about operational transconductance amps. Most of the problem is figuring out when you need a programmable dynamic current source.  
22/ A CMOS output with an emitter follower can drive a 5V relay nicely as the relays normally have a must-make spec of 3.5V. This saves power and require no flyback components.  
23/ Typical thermocouple potential is 30uV/degC. Route signals differentially, along the same path, avoid temp gradients. DPDT latching relays won"t heat up when multiplexing these signals.  
24/ You SHOULD be bothered by a design that looks messy, cluttered or indirect. This uncomfortable feeling is one of the few indications that there"s a better way.  
25/ Avoid drawing any current from the wiper of a potentiometer. The resistance of the wiper contact will cause problems (local heating, noise offsets etc.)  
26/ Most digital phase detectors have a deadband where the analog output does not change over the small range where the 2 inputs are coincident. This often-ignored fact has helped to create some very noisy PLL"s (Use a high val bleeding resistor to always ensure current flow in the deadband)  
27/ The phase noise of a phase-locked VCO will be at least 6dB worse than the phase noise of the divided reference for each octave between the comparison frequency and the VCO output frequency. Avoid low-comparison frequencies.  
28/ You can almost always determine the leads of a bipolar transistor with an ohm meter. b-e and b-c junctions will measure like a diode with the b-c junction reading slightly lower than the b-e junction when forward biased.  
29/ For low distortion, the drains (or collectors) of a differential amp"s front-end should be bootstrapped to the source (or emitter) so that the voltages on the part are not modulated by the input signal.  
30/ If your design uses a $3 op amp, and you will be making a thousand of them, you have just spend $3000. Are you smart enough to figure out how to use a $.30 op amp instead?  
31/ The Q of an LC tank circuit is dominated by the losses in the inductor in terms of series R. Q=omega.L/R  
32/ Leakage current doubles for every 10degC increase in temp.  
33/ When inputs to most JFET op amps exceed the common-mode range for the part, the output may reverse polarity. This artifact will haunt the designers of these parts for the rest of their lives, as it should!  
34/ Understand the difference between "make-before-break" and "break-before-make" when you specify switches.  
35/ 3 Terminal voltage regulators in the TO-220 packages are wonderful parts. They are cheap, rugged, thermally protected and very versatile. Use them virtually any place where you need a protected power transistor. They also make nice AM power-modulators.  
36/ Use step recovery diode where you need fast edges under 100pS (hot-carrier is even faster)  
37/ The old 723 regulator is still one of the lowest noise regulators around! (2.5uVrms 100Hz-10k)  
38/ You can make a very simple oscillator with one diac, cap and a resistor.  
39/ NPN transistors are normally superior to their PNP counterpart in performance.  
40/ Typical spec in some databooks should read "Seen it once". Always work with the worst spec of the part when doing a design.  
41/ Don"t just copy circuits from application notes without understanding completely how it operates, and the reason for the choice of values.  
42/ Dealing with crystals, make sure you understand the difference between series and parallel resonant. In a circuit, crystal frequency can generally be slightly lowered by placing a inductor in series and increased by a capacitor in series.  
43/ Power MOSFETS on-resistance will have a -ve temp coef and not +ve at low current levels. This is important to remember when paralleling devices.  
44/ Lowest noise figure of a RF transistor is not normally where the input is perfectly matched.  
45/ Many un-stable RF devices can be made stable by loading the input or the output by a simple resistor, either in series or parallel.  
46/ You trade gain for bandwidth.  
47/ Push-pull power invertors using bipolars are risky and can saturate the core because of hysteresis stepping (use power fets)  
48/ The Al value of a core will increase up to 50% or more under current transients.  
49/ Be aware of leakage inductance when switching. V=L(dI/dt)  
50/ The harder you turn-on a power transistor, the longer it will take to turn off.( the part where you burn the joules in the device)  
51/ Always remember the Miller guy.  
52/ In fault-finding a circuit, don"t overlook the obvious. (is there power?)  
53/ What is a ground loop, and how to avoid it.  
54/ 120 is a better number than 240 when using LM3XX type adjustable regulators.  
55/ The lower comparator in the old 555 may have quite a long storage time.  
56/ ZERO-ESR caps may do more harm than good.  
57/ A correctly configured audio power amplifier will give more distortion in Class-AB, not less, because of the abrupt gain changes inherent in switching from A to B every cycle.  
58/ Be a STAR when it comes to ground matters.  
59/ Know when you need to use a Zobel network.  
60/ Use current mirrors and mirror your current.  
61/ Heatsink eff decreases with height above sealevel.  
62/ A matt-black heatsink is much better than a shiny one.  
63/ Ignoring secondary breakdown can be costly.  
64/ Understand fuses and fuse ratings, fast and slow. Do you know when to use a semiconductor-fuse?  
65/ Charge balancing resistors are a must when stacking serie-parallel high voltage capacitor banks.  
66/ You must understand DC-restoration otherwise you will have a hard time designing Z-modulation in CRT circuits.  
67/ Display 6 vert div low freq on a scope, increase the freq (make sure the source is constant amplitude) until display drops to 4.2 div. That is the true 3dB BW of the scope. (scope-source impedance should be matched)  
68/ Doing a measurement with your DMM in the ACV position on your DC circuit will give a quick indication of any excess ripple on the supply when you don"t have a scope at hand.  
69/ Dly timebase on a scope is very useful once you figured out when, why and how to use it.  
70/ Know what to expect before you measure, otherwise any measurement is meaningless.  
71/ Op amps. Output will swing in the direction that will force the inv-input level to try come closer to the non-inv input level.  
72/ Understand virtual ground, slew-rate, CMRR and PSRR. (CMRR decrease with increase in freq)  
73/ Making measurements near a spec-analalyzer"s noise floor will give 3dB errors.  
74/ Understand the phase-noise limitations of the analyzer when making such measurements on oscillators.  
75/ In a LC oscillator add some C with -ve temp coef to cancel the +ve temp coef of the L for min drift with temp.  
76/ Less drift will result from making C with a few parallel caps, to reduce the heating effect of the oscillating current when spread out over a larger plate area.  
77/ You will get more tuning range with the same LC combination in a Clapp than in a Colpitts circuit.  
78/ High-Q tuned LC filters will have more insertion loss.  
79/ Williams"s Rule (Guru at Linear Tech) for precision op amp circuits: " Always invert (except when you can"t)"  
80/ Cuk is not a kind of locomotive.  
81/ If you don"t know how to make a design better, find out what makes it worse.  
82/ Sometimes you know just enough to be dangerous.  
83/ Impedance will reflect back as the square of the turns ratio.  
84/ If you could design a component with the characteristics of a finger it could cure many design problems and you will be rich.  
85/ Get nervous when the customer you are trying to help doesn"t even have a scope.  
86/ Specs quoted by reps always exceed those by Engineering.  
87/ A bad (Engineer) workman always blames his tools.  
88/ Don"t believe everything that a SPICE program spits out.  
89/ It is easy to get the color code of a 1kOhm and 12Ohm resistor mixed up when you are in a hurry.  
90/ I bet one could write a thesis about the ability of probes to get tangled-up on a bench.  
91/ DMM can upset sensitive circuits from noise generated inside it.  
92/ When probing directly on a crystal of a uP, use 10kOhm or so resistor in series with the probe tip to prevent loading from stopping the osc.  
93/ It is easier to see what is happening on the ports using a scope when you trigger one chan against the cpu clock.  
94/ National once made a bad op amp many years ago that some Engineers referred to it as "Jelly Beans"  
95/ The moment you can start to notice distortion on an oscilloscope it is already way past being acceptable.  
96/ Be big enough to say "I don"t know", people will respect you more.  
97/ The best designer is often working in the marketing department.  
98/ Some remarkable discoveries/inventions were made by people that knew very little about the subject. Don"t fall into a groove in you thinking process.  
99/ The Peter-Principle : Everybody will be promoted up to his own level of incompetence. http://pespmc1.vub.ac.be/PETERPR.html  
100/ END-Enjoy

社建电子

高手上

cowboy您好

翻译了前50条。
我不是电子专业。
请纠正我，如果我错了，或者你有更好的翻译。
（特别是那些有两个问号的）。

一百条模拟设计经验
1 /电容和电阻有寄生电感，表面黏着的的元件约为0.4nH，引脚式元件约为4nH。
2 /如果您不想一个高带宽的晶体管发生振荡，在至少在3个引脚中的2个引脚放置有损组件。铁氧体磁珠工作 很好。
3 /当在电路中进行直流测量，发现数据没有任何意义，应怀疑有东西在振荡。
4 /运算放大器驱动容性负载时往往振荡。
5 /一个小信号晶体管的基极发射极电压Vbe大约为0.65V并其压降约2mV/degC. Vbe 随温度上升而下降。
6 /用电阻的欧姆值的平方根乘以0.13nV找到1Hz带宽中的噪音。然后再乘以带宽(HZ)的平方根给出了总噪声电压。
7 /约翰逊噪声电流随电阻的增加而下降。
8 /一个晶体管发射极的阻抗在室温为26欧姆/ Ie 毫安。
9 /所有放大器都是差分的，因为它们都总有某处相对于地。
10 /典型金属膜电阻有大约100 ppm/摄氏度 的温度系数。
11 /一个安静的运算放大器的输入噪声电压是1nV/sqrt（赫兹），但很多都可以提供20nV/sqrt（赫兹）的。双极前端运算放大器比FET前端运算放大器具有较低的电压噪声和较高的电流噪声。
12 /使用LC电路作为电源滤波器实际上在过滤器的共振频率里可以使电源噪声倍增。可使用低Q值的电感来克服这种情况。
13 /使用比较器作比较，运算放大器作放大，不要认为可以混合两者使用。
14 /陶瓷电容器, 除NPO介质陶瓷电容器外任何其他介质的，应仅用于旁路的应用。
15 /一个N沟道增强型场效管需求+Ve 栅-源电压，去控制漏-源沟道形状。??
16 /小信号JFETS作为低泄漏二极管是非常好，通过连接在漏极和源极一起日志电流到电压转换器和低漏电输入保护。将小信号双极性管的B-C结绑在一起也会是一个很好的低泄漏二极管。??
17 /低带通滤波器使用贝塞尔低的至少过冲量在时间域和Cauer（或椭圆形）为最快的频率域衰减。??
18 / 分贝总是 2个力率的比例对数的10倍。 ??
19 /在低频时，一个晶体管的集电极电流与其基极应用电流同相。在高频率时电流在集极落后于基极90度。你必须明白这个简单的事实才了解高频振荡器。
20 /最常见的玻璃环氧树脂印刷电路板材料（FR4）有一个约4.3的介电常数，要制作一阻抗特性为100欧姆的线路，使用厚度约为板厚度0.4倍的线路与接地平面成对面。对于一个50欧姆阻抗特性的线路则使用2倍的厚度。
21 /如果你需要一个可编程动态电流源，去了解运算跨导放大器。大部分的问题都可以搞清楚。
22 /一个带射极跟随器的CMOS的输出可以很好的驱动一个5V继电器因为继电器通常有一规格必备的3.5V。这样可以节省电力，也无需反激式元件。
23 /典型热电偶电电位为30uV/degC。差分的传送信号，沿着相同的路径，避免温度梯度。双刀双掷闭锁继电器当复用这些信号时不会发热。

24 /你应该被一个看起来凌乱，杂乱或间接的设计打扰。这不舒服的感觉是少数迹象之一，表明有一个更好的方法。
25 /避免从一个可变电阻的滑动接点脚取电流。该接点的接触电阻会导致问题（局部加热，噪声偏移等）。
26 /大多数的数字相位检测器有一个死波段是在2个输入重合时的小范围模拟输出不会改变。这个往往被忽视的事实有助于建立一些非常嘈杂的锁相环（使用高阻值出血电阻以确保始终在死波段有电流流）。
27 /一个锁相压控振荡器的相位噪声将至少6dB逊于参考的划分的每个八度之间的比较频率和压控振荡器输出频率的相位噪声。??
28 /你几乎总是能利用一个欧姆表去确定双极型晶体管的接脚。B-E结和B-C结就像测量正向偏置的二极管，BC结测量得的读数将略低于B-E结的读数。
29 /对于低失真，前端差分放大器的漏极（或集极），应自举到源极（或射极），以便于零件的电压不受输入信号调制。
30 /如果你的设计采用3美元的运算放大器，而你需要生产一千套，你要花3000美元。你是否够聪明会去弄清楚如何使用0.30美元的运算放大器取代呢？
31 /一个LC谐振电路的Q值主要由电感中以串列形式的等效电阻R的损失。Q = omega.L /R。
32 /每增加10degC的温度泄漏电流将双倍增加。
33 /当大多数JFET运算放大器的输入超过该部件的共模范围，输出可能反极性。这现像将会终生困扰这些零件的设计者，因为它应该！
34 /你指定使用开关时要了解“先接后断”和“先断后接” 之间的差异。
35 / TO - 220封装的3端稳压器是美妙的部件。他们很便宜，坚固耐用，带热保护，非常灵活。在几乎任何你需要一个受保护的功率晶体管的地方可以使用它们。它们还可以做成不错的调幅功率调制器。
36 /用阶跃恢复二极管，当您需要100ps以下的快速边沿（热载流子甚至更快）。
37 /老LM723稳压器仍是最低噪声的稳压器之一！ （2.5uVrms 100Hz- 10K的）。
38 /你可以用一个交流二极管，电容和一个电阻制作一个非常简单的振荡器。
39 / NPN晶体管在性能上通常优于对应的NPN晶体管。
40 /在一些数据手册中的典型规范，应改为“见过一次。当我们作
一个设计时总是使用元件最差的规范。
41 /在没有完全理解它是如何运作，以及所选择数值的原因时，不要只从应用笔记中复制应用电路。
42 /处理晶振时，请确保您理解串联和并联谐振之间的区别。
在电路中，晶体频率一般都可以通过放置一个串联电感略微降低和一个串联电容略微增加。
43 /功率MOSFET的导通电阻在低电流水平时将有一个 - Ve 的温度系数而不是 Ve。当并联元件时这一点很重要要记住。
44 /射频晶体管的最低噪声数字通常不会在输入是完全匹配的地方。
45 /许多不稳定的射频器件，可通过加载输入或输出通过一个简单的电
46 /你以增益交换带宽。
47 /采用双极管的推拉式电源换流器是有风险的，由于滞后步进（使用功率FET）可以使核心饱和。
48 /在瞬态电流下，一个核心的AL值将上升50％或以上。
49 /使用开关管时要知道存在漏感。 V=L（dI / dt）
50 /你越的困难接通电源晶体管，关闭它的时间越长。（在你燃烧器件内的焦耳）。

cowboy您好

51 - 100条

51 /永远记得米勒的家伙。
52 /在为电路排除故障时，不要忽略了显而易见的的事情。 （是否有电力？）
53 /什么是接地回路，以及如何避免它。
54 /使用LM3XX式可调稳压器时120比240是更好的数字。
55 /在旧555较低的比较器可能有相当长的储存时间。
56 /零等效串联电阻（ZERO-ESR）电容可能弊多于利。
57 /一个正确配置的AB类音频功率放大器将更多地，而不是更少的失真，由于从A切换到B的每一个周期固有的突发增益都在变化。
58 /当谈到对地事宜时，使用STAR，。
59 /你要知道什么时候需要使用Zobel网络。
60 /使用电流镜子，折射出你的电流。??

61 /散热片的效率于海平面以上高度效率下降。
62 /亚光黑色散热片比一个闪亮的更好。
63 /忽略次要故障可能是昂贵的。
64 /理解保险丝及保险丝额定值，快速和缓慢。你知道什么时候使用的半导体保险丝吗？
65 /当堆叠串-并联高压电容器时，电荷平衡电阻是必须的。
66 /你必须了解DC -恢复，否则当你在CRT电路设计Z -调制时你将有一个艰难的时间。
67 / 在示波器上显示6垂直分度的低频率，增加频率（确保源是恒定的振幅），直到显示下降到4.2分度。这是示波器真正的3dB带宽。 （示波器-源的阻抗应该匹配）。
68 /当你手边没有示波器时用数字万用表直流电压档测量你的直流电路将是给予电源电压上有没有任何过剩的涟漪的快速指示。
69 / 在示波器上DIY一个时基是非常有用的，一旦你想通了的什么时候，为什么和如何使用它。
70 /知道了你期待会是什么结果，然后再测量，否则任何测量是没有意义的。
71 /运算放大器。输出将向一个方向摆动这将迫使反相输入端的电平，试图更接近非反相输入端电平。
72 /了解虚拟接地，摆率，共模抑制比(CMRR)和电源抑制比(PSRR)。 （共模抑制比随频率的增加而下低）。
73 /在一个频谱分析仪的本底噪声附近进行测量会出现3dB的误差。
74 /对振荡器进行测量时了解分析仪对相位噪声的限制。
75 /在一个LC振荡器添加一些负温度系数的电容抑制取消电感的正温度系数使达到最小的温度漂移。
76 /由几个并联电容器组成C将导致较小漂移，当分散在一个较大的板块区域时可以减少热效应的振荡电流。
77 /相同感容的组合下你会在Clapp电路较考毕兹电路得到更多调谐范围。
78 /高Q值调谐LC滤波器将有更多的插入损耗。
79 /威廉姆斯的定律（在直线科技的大师）的精密运算放大器电路：“一直反向（除非你不能）”。
80 /Cuk不是一种机车。??
81 /如果你不知道怎样做一个更好的设计，找出是什么使它变得更糟。
82 /有时候你知道得刚刚够是危险的。
83 /阻抗会反射回来作为匝数比的平方。
84 /如果你能设计出一个有手指特点的组件它可以解决许多设计上的问题，你就会富裕。
85 /当你想帮助的顾客甚至没有一个示波器你应该感到紧张。
86 /销售代表引述的规格总是超过工程部的。
的代表规格报价超过工程的始终。
87 /一个不好的（工程师）工匠总怪他的工具。
88 /不要相信一切由特别为集成电路模拟的程式(SPICE)程序吐出来的东西。
89 /当你在赶时间时，是很容易搞混一个1K欧姆和一个12欧姆的电阻颜色代码。
90 /我敢打赌，任何人都可以写一篇论文关于探针纠缠工作台的能力
91 /从数字万用表里面产生的噪声可以破坏敏感的电路。
92 /当直接探测一个微型处理器的晶体，使用10K欧姆左右的电阻，与探针头串联，以防止振荡器停振。
93 /使用示波器是比较容易看到在端口发生什么，当你以CPU时钟去触发一个通道时。
94 /许多年前美国国家半导体曾做了一个非常坏的运算放大器，一些工程师称它是“果冻豆” 。
95 /在你开始可以注意到一个示波器失真的那一刻， 它已经是远远过去了可被接受的时间。
96 /大大方方地说：“我不知道”，人们会更加尊重你。
97 /最好的设计师往往是在营销部门工作。
98 /一些显着的发现/发明，都是由知道关于这个问题很少的人所创造
在你的思维过程不要陷入深沟。
99 /彼得的原理：每个人都将晋升到他自己不能胜任的水平。
http://pespmc1.vub.ac.be/PETERPR.html
100 /结束-享受

cowboy您好

让我试试 3

cowboy您好

翻译了前50条。(在三楼)
我不是电子专业。
如果我翻译错了，或者你有更好的翻译，请纠正我。（特别是那些有两个问号的）。

gdi2045

51/牢记米勒电容效应
52/在检查电路错误时,不要忽视最明显的地方(是否接通电源了?)
53/什么是接地环路,以及如何避免--使电源线与地线尽量平行，保持地平面的完整，信号线与地线平行，屏蔽线等
54/当使用LM3XX可调稳压器时,120欧姆的调节电阻比240欧姆要更好
55/旧的555芯片中的比较器会有相当长的存储时间
56/特别低ESR的电容可能弊大于利,譬如在某些线性稳压器做滤波器时，很容易导致震荡，从而性能下降
57/即使是一个正确设计的AB类音频功率放大器也会比A类功率放大器带来更大的信号失真，因为每个周期中从A类到B类的转换都使增益发生了变化
58/地线尽量星形走线
59/知道如何正确应用Zobel网络
60/使用镜像电流源反映电流
61/散热片的效率和丝印面上的高度成正比
62/散热片黑色的比白色的好
63/忽视二次击穿的代价很高
64/掌握保险丝的参数,动作的快慢,知道什么时候运用半导体保险丝
65/当串并联高压电容时必须使用电荷平衡电阻
66/在设计Z调制CRT电路时必须要考虑直流恢复时间
67/在示波器上用6格的幅度表示低频，慢慢增大频率（确保信号源幅值不变）；当信号降到4.2格时，就得到了示波器3dB带宽（输入阻抗要匹配）
68/没有示波器时,用数字万用表的交流电压档同样可以显示直流电路的电源纹波
69/示波器的触发延时在正确应用时非常有用
70/对测量结果正确估计,否则一切测量都没有意义

gdi2045

网上有些参考翻译:
1/ Capacitors and resistors have parasitic inductance, about 0.4nH for surface mount and 4nH for a leaded component.   
1. 电阻跟电容都有寄生电感，贴片封装的大概0.4nH，插件的大概4nH。
2/ Capacitors and resistors have parasitic inductance, about 0.4nH for surface mount and 4nH for a leaded component.
2.如果你不想通过在高带宽晶体管三个引脚中的至少两个引脚放置损耗元件的方法消除振荡.铁氧体磁珠会起到很好的作用.
3/ When taking DC measurements in a circuit and they don"t make sense, suspect that something is oscillating.  
3.对一个电路直流测试时，电路工作不正常，应该怀疑有元件在振荡
4  Opamps will often oscillate when driving capacitive loads.
4  运放在驱动容性负载时经常会震荡。
5/ The base-emitter voltage Vbe of a small signal transistor is about 0.65v and drops about 2mV/deg C. Vbe goes down with increasing temp.
5/ 小信号晶体管的基-射极电压Vbe大约是0.65伏特，大约以2毫伏/摄氏度的速度降低。Vbe随着温度的升高而降低。
6/ Multiply 0.13nV by the square root of the ohmic value of a resistor to find the noise in a 1Hz bandwidth. Then multiply by the square root of the BW in Hz gives the total noise voltage.
6/ 电阻阻值的平方根，乘以0.13纳伏，可以得到1赫兹带宽的噪声。再乘以以赫兹为单位的带宽的平方根，可以得到总噪声电压。
7 Johnson noise current goes down with a increase in resistance.  
7 Johnson噪声电流随着电阻的增加而降低.
8/ The impedance looking into the emitter of a transistor at room temp is 26Ohm/Ie in mA   
室温下晶体管射极阻抗为26欧姆/mA  
9/ All amplifiers are differential in that they are referenced to ground somewhere.  
所有的放大器都是相对于某个地电平的差分放大。
10/ Typical metal film resistor has a temp coef of about 100 ppm/deg C  
（典型的金属薄膜电阻具备100 ppm/deg C的温度系数）

11/ The input noise voltage of a quiet op amp is 1nv/sqrt(Hz) but there are plenty available with 20nV/sqrt(Hz). Op amps with bipolar front-ends have lower voltage noise and higher current noise than those with FET front-ends  
（低噪音运放的输入噪声电压可以达到1nv/sqrt(Hz) ，但是我们大量用到的运放具有20nV/sqrt(Hz)的输入噪音。双极晶体管结构比FET结构的运算放大器具备更低的电压噪声和更高的电流噪声，所以如果前级输入的是电压信号则采用双极型输入，而如果是高阻抗型的电流输入信号，则必须使用FET结构的）

12/ Using an LC circuit as a power supply filter can actually multiply the power supply noise at the filter"s resonant frequency. Use inductor with low Q to overcome this.  
（用LC滤波器对电源滤波将会增加电源在滤波器谐振频率点上的噪声，通过选择低Q的电感可以有效克服这一点。）

13/ Use comparators for comparing and op amps for amplifying and don"t even think of mixing the two.
（用比较器进行比较，用运放进行放大，千万不要搞混。）

14/ Ceramic caps with any other dielectric other than NPO should only be used for bypass applications.
（ 除高频瓷片电容外的瓷片电容仅可用作旁路电容）
  
15/ An N-channel enhancement-mode FET needs +ve voltage on the gate-source to conduct form drain-source.  
  （n沟道增强型mosfet需要在gate-source 间接入正电压来控制drain-source间的电流Ids）

16/ Small signal JFETS work very well as low-leakage diodes by connecting drain & source together in log current-to-voltage converters and low leakage input protection. Small signal bipolars with b-c tied together will also make nice low-leakage diodes.  
（JFETS短接源漏极在小信号电流-电压转换和输入保护方面具备和低泄漏二极管媲美的特性，小信号测量中晶体管B-E极短接也相当于一个优异的低泄漏二极管）。

17/ With low pass filter use Bessel for least amount of overshoot in the time domain, and Cauer (or elliptic) for fastest rolloff in the freq domain. （设计低通滤波器时选用贝塞尔型可以使时域较平坦，没有太多过冲，选用切比雪夫可以提高截止频率的陡峭性。）

18/ dB is always 10 times the log of the ratio of 2 powers.  
（分贝是10*lg的比值。）

19/ At low frequencies, the current in the collector of a transistor is in phase with the applied current at the base. At high frequencies the current at the collector lags by 90deg. You must appreciate this simple fact to understand high frequency oscillators.  
（低频情况下，晶体管集电极电流与基极电流同相，但在高频情况下，集电极电流相位上滞后90度，这有助于你理解高频振荡。）

20/ The most common glass-epoxy PCB material (FR4) has a dielectric constant of about 4.3 To make a trace with a characteristic impedance of 100 Ohm, use a trace thickness of about 0.4 times the thickness of the board with a ground plane on the opposite side. For a 50Ohm trace make it 2 times the thickness.  
（PCB应用最普通的FR4材料的介质常数大约为4.3，印制版线为得到100欧的特征阻抗需要的线宽为PCB板（背面覆铜）厚度的0.4倍，50欧的阻抗需要线宽为板后的2倍。--线长呢？不解）

21/ If you need a programmable dynamic current source, find out about operational transconductance amps. Most of the problem is figuring out when you need a programmable dynamic current source.  
（当你用跨导运算放大器作为可编程动态电流源时你会发现很多问题。）

22/ A CMOS output with an emitter follower can drive a 5V relay nicely as the relays normally have a must-make spec of 3.5V. This saves power and require no flyback components.  
（CMOS输出配合一个射极跟随器可以很好的驱动一个5V工作的继电器（必须是3.5V以上才能正常工作），这样节省了功率并不需要反馈元件）。

23/ Typical thermocouple potential is 30uV/degC. Route signals differentially, along the same path, avoid temp gradients. DPDT latching relays won"t heat up when multiplexing these signals.  
（典型的热电偶电位是 30uV/degC，布线是差分信号要尽量走同样的路径避免差分线上产生温度梯度。当需要切换这些信号时，双刀双掷常闭继电器可以避免切换过程中产生的热量，影响热电偶温度测量的精度。）

24/ You SHOULD be bothered by a design that looks messy, cluttered or indirect. This uncomfortable feeling is one of the few indications that there"s a better way.  
（你可能会直接或间接的感到设计的电路感混乱不堪，这种不好的感觉其实是一种很宝贵的暗示，那就是那肯定还有一直能够更好的设计路径）

25/ Avoid drawing any current from the wiper of a potentiometer. The resistance of the wiper contact will cause problems (local heating, noise offsets etc.)  
（避免任何的电流都可以从电位器分压而得，电位器相关的阻抗可能回导致一些问题，如局部加热，噪声，偏移等）

26/ Most digital phase detectors have a deadband where the analog output does not change over the small range where the 2 inputs are coincident. This often-ignored fact has helped to create some very noisy PLL"s (Use a high val bleeding resistor to always ensure current flow in the deadband)  
（数字鉴相器有一个死区，就是模拟输出在一个很小的范围内（双端输入一致的情况下）不改变，这个经常被忽视的事实很容易造成PLL噪声非常大，用一个大阻值的旁漏[泄漏]电阻确保电流注入死区。）
28/ You can almost always determine the leads of a bipolar transistor with an ohm meter. b-e and b-c junctions will measure like a diode with the b-c junction reading slightly lower than the b-e junction when forward biased.   
通过电阻表可以分辨三极管的极性。发射结和集电结跟二极管差不多，集电结正向偏置时的读数要稍小于发射结。

30/ If your design uses a $3 op amp, and you will be making a thousand of them, you have just spend $3000. Are you smart enough to figure out how to use a $.30 op amp instead?   
3元一个的运放生产一千个就是3000元。为了节约成本，可以想办法用0.3元的运放替代。

32/ Leakage current doubles for every 10degC increase in temp.
温度每提高10度，漏电流就扩大一倍。

34/ Understand the difference between "make-before-break" and "break-before-make" when you specify switches.  
在选择开关时，弄清楚先接后断和先断后接的区别。
35/ 3 Terminal voltage regulators in the TO-220 packages are wonderful parts. They are cheap, rugged, thermally protected and very versatile. Use them virtually any place where you need a protected power transistor. They also make nice AM power-modulators.
35/TO-220封装的三端稳压器是非常棒的电子器件。它们便宜、坚固、具有热保护功能、并且有多种用途。在你想要用到电源保护功能的地方几乎都能看到它。它们也具有很出色的电源调幅功能
37/ The old 723 regulator is still one of the lowest noise regulators around! (2.5uVrms 100Hz-10k)   
略显老旧的723仍然是噪声最低的稳压器之一 (2.5uVrms 100Hz-10k) 。


39/ NPN transistors are normally superior to their PNP counterpart in performance.   
NPN管通常比对应的PNP管性能好。
38/ You can make a very simple oscillator with one diac, cap and a resistor.   
你可以通过二极管、电容和电阻制作一个简易的振荡器.
40.对于有些数据手册中的典型参数,我们应该只是看看而已.在作设计的时候,应该总是按照最坏参数来考虑.
41.不要在没有完全理解电路的运行原理和元件的取值原因的情况下,就从应用手册中直接照抄电路.
42.在处理晶振的时候,确定你理解了串联谐振和并联谐振的区别.在电路中,串联一个电感会使晶振的频率产生轻微的降低,串联一个电容会使晶振的频率产生轻微的升高.
43/ Power MOSFETS on-resistance will have a -ve temp coef and not +ve at low current levels. This is important to remember when paralleling devices.   
在低电流的情况下，功率MOSFET的导通电阻拥有负温度系数。对于并联器件的时候这一点尤为重要。
44/ Lowest noise figure of a RF transistor is not normally where the input
44.最低噪声的射频晶体管作为输入时（产生的噪声）也是非比寻常的。
45/ Many un-stable RF devices can be made stable by loading the input or the output by a simple resistor, either in series or parallel.  
许多不稳定的射频器件，可通过加载一个简单的电阻到输入或输出端使之稳定，无论串联或是并联。
46/ You trade gain for bandwidth.  
46 带宽使你获益。
47/ Push-pull power invertors using bipolars are risky and can saturate the core because of hysteresis stepping (use power fets)  
47 /推挽逆变电源用双极晶体管是有风险的，由于磁滞可致铁心饱和（用功率场效应管<FET>）
48/ The Al value of a core will increase up to 50% or more under current transients.  
49/ Be aware of leakage inductance when switching. V=L(dI/dt)  
做开关电源时要注意漏电感的影响
50/ The harder you turn-on a power transistor, the longer it will take to turn off.( the part where you burn the joules in the device)
越难导通一个功率晶体管，你就越难关闭它
51/ Always remember the Miller guy.  
始终要记得米勒电容效应
52/ In fault-finding a circuit, don"t overlook the obvious. (is there power?)  
对一个电路查找问题时，不要忽略那些最显眼的位置
53/ What is a ground loop, and how to avoid it.  
要知道什么是地线回路，并知道如何去避免它,使电源线与地线尽量平行，保持地平面的完整，信号线与地线平行，屏蔽线等
54/ 120 is a better number than 240 when using LM3XX type adjustable regulators.  
对于LM3XX系列的可调稳压器，120欧姆的调节电阻比240欧姆要更好
55/ The lower comparator in the old 555 may have quite a long storage time.  

56/ ZERO-ESR caps may do more harm than good.  
特别低ESR的电容可能更会在电路设计中出现问题，譬如在某些线性稳压器做滤波器时，很容易导致震荡，从而性能下降
57/ A correctly configured audio power amplifier will give more distortion in Class-AB, not less, because of the abrupt gain changes inherent in switching from A to B every cycle.  
即使是一个正确设计的AB类音频功率放大器也会比A类功率放大器带来更大的信号失真，因此在每个周期中A到B的切换都使得增益发生了变化
58/ Be a STAR when it comes to ground matters.  
对于地线而言，尽量是星形连接
59/ Know when you need to use a Zobel network.  

60/ Use current mirrors and mirror your current.   
使用镜像电流源反映电流。
61/ Heatsink eff decreases with height above sealevel.   
散热片的效率与其在丝印面上的高度成正比。
62/ A matt-black heatsink is much better than a shiny one.   
黑色的散热片比白色的好。
63/ Ignoring secondary breakdown can be costly.   
忽略二次击穿的代价会很高。
64/ Understand fuses and fuse ratings, fast and slow. Do you know when to use a semiconductor-fuse?   
掌握保险丝和保险丝的等级，动作快还是慢。什么时候用半导体保险丝。
65/ Charge balancing resistors are a must when stacking serie-parallel high voltage capacitor banks.   
串并联高压电容器（高电压大容量电容器）必须使用充电电阻。
66/ You must understand DC-restoration otherwise you will have a hard time designing Z-modulation in CRT circuits.
必须懂得DC-restoration ，否则在设计CTR Z调制电路时犯难。
   
67/ Display 6 vert div low freq on a scope, increase the freq (make sure the source is constant amplitude) until display drops to 4.2 div. That is the true 3dB BW of the scope. (scope-source impedance should be matched)   
在示波器上用6格的幅度表示低频，慢慢增大频率（确保信号源幅值不变）；当信号降到4.2格时，就得到了示波器3dB带宽（输入阻抗要匹配）
68/ Doing a measurement with your DMM in the ACV position on your DC circuit will give a quick indication of any excess ripple on the supply when you don"t have a scope at hand.   
当你没有示波器在时，使用数字万用表的门交流电压档可以很容易到直流电路的电源纹波值。

69/ Dly timebase on a scope is very useful once you figured out when, why and how to use it.   

示波器上的时基延时（好像是触发延时吧）非常有用；一旦你知道什么时候使用，为什么使用，怎么样使用时基延时的时候。
72/ Understand virtual ground, slew-rate, CMRR and PSRR. (CMRR decrease with increase in freq)   
理解虚地、摆率、共模抑制比和电源抑制比.(共模抑制比随着频率的升高而下降)
73/ Making measurements near a spec-analyzer"s noise floor will give 3dB errors.   
在频谱仪的噪声层附近测量会引起3dB的误差
74/ Understand the phase-noise limitations of the analyzer when making such measurements on oscillators.   
测量振荡器时，理解相位噪声对仪器的限制
75/ In a LC oscillator add some C with -ve temp coef to cancel the +ve temp coef of the L for min drift with temp.  
在LC振荡器种，加入具有负温度系数的电容来抵消电感的正温度系数，减小温飘
76/ Less drift will result from making C with a few parallel caps, to reduce the heating effect of the oscillating current when spread out over a larger plate area.   
通过并联多个电容的方式得到一个振荡电路的电容器，可以减小振荡电流流过较大平面时的热效应而引起的飘移。
77/ You will get more tuning range with the same LC combination in a Clapp than in a Colpitts circuit.   
使用相同的LC组合，使用克拉普振荡器可以获得比考比茨振荡器更大的调谐范围
78/ High-Q tuned LC filters will have more insertion loss.   
高Q值的LC滤波器有更大的接入损耗
79/ Williams"s Rule (Guru at Linear Tech) for precision op amp circuits: " Always invert (except when you can"t)"  
高精度运放放大电路的 威廉姆法则（来自Linear Tech的大师）：“永远反向（除非在你做不到的时候）”
80/ Cuk is not a kind of locomotive.   
库克直流斩波电路并不是一种（机车？我的理解是不能简单的当成把低压电源变成高压电源，因为库克电路不能提高带负载能力）
82/ Sometimes you know just enough to be dangerous.   
有时候，你知道的东西不多不少，刚好能使你陷入危险（似懂非懂的时候莫装13）
83/ Impedance will reflect back as the square of the turns ratio.   
阻抗会以匝数比之平方反射回去(阻抗变换)
84/ If you could design a component with the characteristics of a finger it could cure many design problems and you will be rich.   
如果你能使用手指的特点（OMG召唤英语帝，我晕了，是徒手的意思吗？）设计一个元件，那么这将会改正设计中的许多错误，你就会变得富有了（你赚的就多了）（我理解的是，如果你有徒手设计计算一个元件的功力了，就进阶为高手了）
85/ Get nervous when the customer you are trying to help doesn"t even have a scope.   
如果你尽力想要帮助的顾客一点都不理解（你说的东西），那么要从你自身找原因（好吧，意译的比较严重）
86/ Specs quoted by reps always exceed those by Engineering.   
推销员给出的规格总是优于工程师所给出的
87/ A bad (Engineer) workman always blames his tools.   
差劲的工程师总是怪罪他的工具
88/ Don"t believe everything that a SPICE program spits out.   
永远不要相信任何SPICE仿真给出的结果
89/ It is easy to get the color code of a 1kOhm and 12Ohm resistor mixed up when you are in a hurry.   
匆匆忙忙时容易把12欧的色环电阻与1K的色环弄混（莫着急）
90/ I bet one could write a thesis about the ability of probes to get tangled-up on a bench.   
我打赌一个能写一篇关于探针能力的论文的人，在工作台上将无限纠结……
92/ When probing directly on a crystal of a uP, use 10kOhm or so resistor in series with the probe tip to prevent loading from stopping the osc.   
92.如果要直接在晶体引脚上面测试（比如万用表表笔或示波器探针），应该串联一个10K欧姆的电阻再测试，防止外部干扰窜入振荡回路或者说破坏原来的振荡状态。
93/ It is easier to see what is happening on the ports using a scope when you trigger one chan against the cpu clock.  
93/ 有时候,当你试着用CPU的反相钟来触发一个示波器通道时，也许更容易发现“端口”发生了什么故障（或问题）。
94/ National Semiconductor once made a bad op amp many years ago that some Engineers referred to it as "Jelly Beans"   
国家半导体公司很多年前生产过一颗坏运放，有些工程师称之为“果冻豆”。（寓意：要有怀疑的眼光看问题？）

95/ The moment you can start to notice distortion on an oscilloscope it is already way past being acceptable.   
当你开始注意到示波器上的失真，其实它已经是在过去就被接受了的方式。

96/ Be big enough to say "I don"t know", people will respect you more.   
大声说：“我不知道”，人们将更尊重你。

97/ The best designer is often working in the marketing department.   
最好的工程师常常在市场部门工作。

98/ Some remarkable discoveries/inventions were made by people that knew very little about the subject. Don't fall into a groove in you thinking process.   
作出某些显着的发现/发明的人，其实他们对于这个课题了解并不多。不要在你的思考过程中养成一种习惯。意思是做出非凡成就，或者重大发明的往往不是本行业的人。

99/ The Peter-Principle : Everybody will be promoted up his own level of incompetence.  
彼得原理：每个人都将提高到他自己的知识水平（关于彼得原理的连接：http://pespmc1.vub.ac.be/PETERPR.html）。

cowboy您好

LS 翻译的比我好。

kjspace

都是高手！虚心向你们学习！你是英语过几级了！