Jump to content
Electronics-Lab.com Community

nickagian

Members
  • Posts

    45
  • Joined

  • Last visited

    Never

Posts posted by nickagian

  1. Can anybody help me with the following circuit? As you can see it is about a CMOS OpAmp, with cascode input stage. I want to find a way to bias M3,M4 (Vb) but until now I cannot manage it. Can anybody suggest me a solution for biasing and how to calculate it (I mean the W/L ratio of the MOSFETs used, considering that I want a current of 1.5mA on both M1 and M2 tails and a bias voltage Vb of about 2V).

    post-15243-14279143033465_thumb.jpg

  2. Hello everybody! I have to complete a design of an OpAmp using CMOS technology and the given model for the nMOS transistors is the following:

    .model Mn NMOS(LEVEL=2 LD=0.1e-6 VTO=0.77 KP=77e-6 GAMMA=0.35 PHI=0.76 CJ=0.31e-3
    +CJSW=0.17e-9 CGSO=0.19e-9 CGDO=0.19e-9 CGBO=0.3e-9 NSUB=1.9e16 NFS=1e10 TOX=200e-10
    +XJ=0.14e-6 UCRIT=1.5e4 UEXP=0.077 DELTA=2 KF=4e-13 AF=1.2)

    My problem is that I am not sure what exactly is the formula that computes the Idrain of the MOS.

    Of course we know that in saturation

    ID=k*(W/L)*(VGS-Vth)^2, where k=K/(1+

×
  • Create New...