Design of a Novel 62.94dB Gain, 1.31 % THD Folded Cascode Operational Amplifier in 45 nm Technology with In-Depth Analysis, and Layout Verification

The proliferation of modern integrated circuits has ushered in a new era of electronic systems, where operational amplifiers (op-amps) play a vital role in ensuring high-performance circuit design. This research article presents an in-depth investigation into implementing, analyzing, and characterizing a Folded Cascode Operational Amplifier implemented in a 45 nm CMOS technology, emphasizing its robustness and versatility in various circuit topologies. Folded Cascode op-amps are essential for attaining high gain, wide bandwidth, and reduced sensitivity to process variations in integrated circuit design. It differentiates as the shared voltage input mode level reaches near the supply voltage. Rigorous simulations were conducted to assess the suitability and reliability of the design. Simulation results showed a DC gain of 62.94 dB and a phase margin of 50.93 degrees at a unity gain bandwidth of 348.9 MHz. PVTC and Monte Carlo simulations were also analyzed to quantify the influence of process variations and estimate the range of possible outcomes. Finally, the research comprises layout verification, such as ERC, LVS, and DRC, to ensure the physical layout mirrors the intended design and meets industry standards.