原文《A Basic Introduction to the gm ID-Based Design》的第10页,在副标题“What about ro?”往下数3行。In practice ,we usually either want ro>>RL so that ro can be ignored,我认为有误,应该是ro<<RL
" In practice ,we usually either want ro>>RL so that ro can be ignored"这句话没什么问题,我们计算放大器增益是Av=gm(RL//ro),所以增益与ro,RL都相关。
当ro很大,增益由RL决定;RL很大时,增益由ro决定,这是相对的。