The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design >> Analog Design >> large swing output stage
https://designers-guide.org/forum/YaBB.pl?num=1287883067

Message started by Le Deng on Oct 23^rd, 2010, 6:17pm

Title: large swing output stage
Post by Le Deng on Oct 23^rd, 2010, 6:17pm

Hi everyone, I'm doing a project of two stage op amp, differential input as the first stage and common source as the second stage. As it is assumed a 5k resistor on the load, I need an output stage. The project spec requires that the output swing to be within 0.5v of upper and lower rail. I was planning to use a source follower but it doesn't work, because the source follower is gate input and source output and in this case, there is a minimum Vdsat+Vth voltage difference either on upper or lower rail. I'm a little bit stuck on this problem. Can someone give me some advice? Thanks!