Design of an Operational Amplifier for Bandgap Reference Applications
Yuancheng Li · Advances in engineering research/Advances in Engineering Research · 2025
This paper presents the design and simulation of a two-stage CMOS operational amplifier tailored for bandgap reference applications.The proposed architecture comprises a differential input stage, a high-gain amplification stage, and a Miller compensation network to ensure high DC gain, low power dissipation, and stable dynamic performance.Key design considerations include the optimization of transistor dimensions, biasing currents, and frequency compensation techniques to achieve robust stability and enhanced performance.The amplifier is designed to maintain a phase margin exceeding 40 degrees, thereby ensuring stability across process, voltage, and temperature variations.Furthermore, a -3 dB bandwidth of 3 kHz is achieved, rendering the design suitable for precision low-frequency applications.Post-layout simulations based on a 180 nm CMOS process confirm that the proposed amplifier attains a DC gain of 80 dB while maintaining an ultra-low power consumption of 6 µA.These results validate the circuit's suitability for precision analog applications requiring stable reference voltage generation in low-power systems.