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OTA DESIGN and COMPENSATION. Two stage CMOS Feedback and Compensation. Basic Two Stage OTA/OPAMP. Avol = Av1 * Av2 GBP = gm1/CL Lower input Noise than Folded Cascode Compensation- Miller and Pole-Zero cancellation Open Loop gain comparable to Folded Cascoded
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OTA DESIGN and COMPENSATION Two stage CMOS Feedback and Compensation
Basic Two Stage OTA/OPAMP • Avol = Av1 * Av2 • GBP = gm1/CL • Lower input Noise than Folded Cascode • Compensation- Miller and Pole-Zero cancellation • Open Loop gain comparable to Folded Cascoded • Wider Output Swing than Folded Cascode • Lower GBP than Folded Cascode
p vs n Diff pair • best SR/ mW • Allows follower and gain stages poles further separation from the GBP • Improved Noise performance due to 1/f behavior of PMOS vs NMOS • In n-well processes n-follower can not be body tied