鉴于很多电子初学者对什么是TTL电平,什么是CMOS电平不清楚.也不能了解CMOS电平与TTL电平的区别.特别在网上找到这篇TTL和CMOS电平总结.感谢作者的工作.-In view of the many electronic beginners What is TTL level CMOS level is not clear. Nor to understand the difference between the CMOS level and TTL level find online, especially in this TTL and CMOS level summary of thanks to the author' s work .