Design of a Low-Power Operational Amplifier for Real-Time Signal Processing System of Microsensor

A low-power complementary metal oxide semiconductor(CMOS) operational amplifier(op-amp) is proposed for real-time signal processing system of microsensor. This proposed implementation was based on traditional folded cascode op-amp architecture with positive channel metal oxide semiconductor (PMOS) differential input transistors, which is the best choice for lower-power applications. Simultaneously the wide swing cascode current mirror with sufficient output swing under the low supply voltage is applied to eliminate external bias voltages and related biasing circuit, which are beneficial to further reduce the power consumption. Combined with the theory calculation and computer simulation, the design is implemented in SMIC 1P6M 0.18um 1.8V CMOS technology, with satisfied results. The power is only 0.22 mW.