170 MHz GBW, two stage CMOS operational amplifier with high slew rate using 180 nm technology

Operational amplifiers (Op-amp) are vital components of any analog IC, improving its performance has a significant effect on the entire design. Among different approaches to realize an Op-amp, a Two stage i.e differential amplifier followed by common source amplifier is simple, elegant and occupies less space. The proposed paper presents design of a Two Stage CMOS Operational amplifier, which operates at ±1.8V power supply using 180 nm CMOS technology. The unity-gain bandwidth of the amplifier is 170 MHz. The Op-amp is internally frequency compensated using a miller capacitor for better stability and phase lag created by the zero is resolved by adding a resistor in series with the miller capacitor. The proposed Op-amp provides a slew rate of 189V/µs during rising edge and 227V/µs during falling edge. The circuit offers a open loop Gain of 60 dB with 79 degree phase margin. The designed system is relatively suitable for low power and high frequency applications.