Hi,
Need some urgent help, this is from an exam question. The question requires
us to work out the expression for Io/Vi
This is what i have tried so far,
oamp 1 e+ = (Vi/2)
using e+ = e The base of transistor is now Vi/2,
i assumed Ve = Vi/2 as well (or should it be Vi/2  0.7)
Now ie = Vi/2/R3 and ie = ic thus Vc = Vi/2 + 0.2 (say saturated)
Now e+ of opamp2 is (Vi/2 + 0.2) say Vi/2 again thus e = Vi/2
Thus the voltage drop across the resistors is VVi/2.
Not sure after this, i understand some aspects of the PMOS, when VGS is < Vt then current flows.
I have attached the diagram for reference.
Need some urgent help, this is from an exam question. The question requires
us to work out the expression for Io/Vi
This is what i have tried so far,
oamp 1 e+ = (Vi/2)
using e+ = e The base of transistor is now Vi/2,
i assumed Ve = Vi/2 as well (or should it be Vi/2  0.7)
Now ie = Vi/2/R3 and ie = ic thus Vc = Vi/2 + 0.2 (say saturated)
Now e+ of opamp2 is (Vi/2 + 0.2) say Vi/2 again thus e = Vi/2
Thus the voltage drop across the resistors is VVi/2.
Not sure after this, i understand some aspects of the PMOS, when VGS is < Vt then current flows.
I have attached the diagram for reference.
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