Three-Stage Operational Amplifier with Frequency Compensation Using Cascade Zero

Short channel MOSFET exhibits the characteristics of wide bandwidth and low DC gain. A gain causes a high error narrow output linear range in closed loop. The gains can be improved by using cascade structure, but frequency compensation is required due to increase number poles. nodes each stage Common-Source amplifier have zero, this zero cancelled out input node next stage. This paper proposes three-stage operational (op-amp) with zero. op-amp was implemented 180 nm CMOS technology achieved 86.96 MHz unity–gain frequency, 51.7° phase margin at 32 pF load capacitor 99.83 dB gain, that is, 36.21 improvement over two-stage same power consumption. consumed 7.74 mW supply voltage 1.8 V.