Given this amplifier:

Supply voltages are: UCC = 15V, UEE = -15V. Remember decoupling capacitors.

During the calculations, you regard the opamps as ideal.

To compensate for this amplifier, you will only be allowed to change the circuit around U1, the last opamp. The rest of the circuit should be unchanged. It should be compensated so that the gain margin 15dB, phase margin 70^o and crossover frequency as high as possible with the given requirements. The loop gain at very low frequencies should be the same for the compensated amplifier as for the uncompensated.

You can determine the loop gain by breaking the loop in node N1.

Compensate the amplifier so that the requirements above are met. Show using simulation in OrCAD that the requirements are met: 20lg | T (j) | Angle T (j) GM

C3 C2 C1 R5 2 2nF R3 4T7 R2 R7 OP 27 4 15MEG INN R4 OP 27 4 N1 R1 OP-27 4 UT C3 C2 C1 R5 2 2nF R3 4T7 R2 R7 OP 27 4 15MEG INN R4 OP 27 4 N1 R1 OP-27 4 UT