I am unsure about a question stated as:
"An amplifier has an open loop gain of 2000 with an upper corner frequency of 500Hz. Determine the required feedback fraction to give a midband gain of 120 and determine the new corner frequency."
I found β = 1/500Hz = 0.002
Then the closed loop bandwidth of the amplifier by BWcl = BWol(1+βAol(mid)) = 2.5kHz
Then to find the the new feedback fraction I used β = 1/120 = 0.0083
I'm not sure if I should have kept the closed loop bandwidth found before and got 2.5kHz/(1+0.0083(120)) = 2.252kHz for the new corner frequency.
Is this wrong?
"An amplifier has an open loop gain of 2000 with an upper corner frequency of 500Hz. Determine the required feedback fraction to give a midband gain of 120 and determine the new corner frequency."
I found β = 1/500Hz = 0.002
Then the closed loop bandwidth of the amplifier by BWcl = BWol(1+βAol(mid)) = 2.5kHz
Then to find the the new feedback fraction I used β = 1/120 = 0.0083
I'm not sure if I should have kept the closed loop bandwidth found before and got 2.5kHz/(1+0.0083(120)) = 2.252kHz for the new corner frequency.
Is this wrong?