Hi,everyone.when i worked out the problems of analog cmos integrated circuits chapter 8 feedback ,i found that some of my answers are not exactly the same as the solutions by razavi. For example ,chapter 8 problems 8.16 and 8.17,i got the open gain 18.42 and the feedback factor 0.5 then the loop gain 9.21,while he got different loop gain used -vf/vt. whose solutions is wrong?[][/img][/youtube]
Re: help:Is there some small errors in the solutions by raza
Only took a short look at your solution, watching out for the "first error". (I apologize for this destructive method). I think, that Rd2 must taken into acount in first stage gain in open loop analysis, thus Rs1 || Rf isn't correct here, it should be Rs1 || (Rf + Rd2). In open loop, the output is open, not shorted, so Rd2 is "seen" by the input stage.