firsttimedesigning
Full Member level 1
So I have finished designing this op-amp.(please see the file Op-Amp)
There are few things that I dont understand though.
First of all, I think there are two poles in this circuit because there two stages ( stage 1 is the differential amplifier, stage 2 is the common source with current source load)
Second, when calculating the first pole,
C1 = Cgs7 + Cgd7(1+ abs(A2)) + Cdb4 + Cgd4 + Cdb2 + Cgd2
abs( ) = absolute value of
(please see file pole1)
what i dont understand is that why is Cgd7 multiplied by (1+ abs(A2))?
when calculating the second pole,
C2 = Cgd7(1+ abs(1/A2)) + Cdb7 + Cgd8 + Cdb8
(please see file pole2)
why is Cgd7 multiplied by (1+ abs(1/A2))?
Thanks in advance
There are few things that I dont understand though.
First of all, I think there are two poles in this circuit because there two stages ( stage 1 is the differential amplifier, stage 2 is the common source with current source load)
Second, when calculating the first pole,
C1 = Cgs7 + Cgd7(1+ abs(A2)) + Cdb4 + Cgd4 + Cdb2 + Cgd2
abs( ) = absolute value of
(please see file pole1)
what i dont understand is that why is Cgd7 multiplied by (1+ abs(A2))?
when calculating the second pole,
C2 = Cgd7(1+ abs(1/A2)) + Cdb7 + Cgd8 + Cdb8
(please see file pole2)
why is Cgd7 multiplied by (1+ abs(1/A2))?
Thanks in advance