The Loop-Gain transfer function of a three-pole amplifier is given by:
2p ´ 106 ÷
2p ´104 ÷
where A is the Open-Loop Gain, and β is the Feedback Factor
(a) On the sheet of semi-logarithmic paper supplied, neatly sketch the (straight-line asymptotic approximation) Bode plot of the transfer function Aβ(jf) (magnitude in decibels, and phase in degrees), against the same corresponding frequency axis (in Hz).
(b) Use estimates from your Bode plot to show that this function will lead to instabilities in a negative feedback circuit. Confirm this algebraically.
(c) Insert a dominant pole into the transfer function to provide a phase margin of 45 degrees.
Assume the original poles are fixed. What is value of the dominant pole frequency?
(d) If the low-frequency Closed-Loop Gain magnitude is 100, what is the value of the Gain Margin, in decibels?