基础版图技术毕业论文中英文资料外文翻译文献浅析.doc

基础版图技术毕业论文 中英文资料外文翻译文献 外文资料原文 IC Mask Design：Essential Layout Techniques Christopher Saint and Judy Saint Common Sense Noise Solutions Let’s go through each one of our real word rock band solution, one at a time. We will see how they map across to mask design techniques—what we can do in both the design world and the layout world to achieve some of these noise reductions. Turn Down the volume Our first request was to ask the rock band to turn down their music. Turning down the volume would be like reducing the signal swing in a circuit. In layout there is not a lot we can do to reduce the signal swing. By signal swing I mean the amplitude or value of the voltage that is being wired around the chip. In a digital circuit, for instance, the zero state is represented by 0 volts, whereas the one state can be represented by 5 volts. This is a voltage swing of 5 volts. Now, if we were to reduce that voltage swing to only 2 volts, then we would be switching less energy each time a flip-flop flips. Or flops. That is the direct equivalent of turning the noise generator down, turning the volume down. As we mentioned in the opening thoughts to this chapter, mainly the digital part of a mixed signal chip is the section that needs to be quieted. So, if you can get a digital logic family that is inherently quiet, i.e., that has very small voltage swings, then that helps keep the overall noise down from the start. Voltage swing is not primarily a layout issue, but is can be, to a certain point. Suppose your circuit designers come along and say they have a chip for you to layout, with a reasonably high chunk of digital circuitry. They have indicated that they plan to use this certain library, which you know is a 5-volt swing library. You remember that you used a digital library on a similar chip some time back that had a 2-volt logic swing. You can turn around and say, “Well, are we worried about noise? Because there is this 2-volt swing library t