A bio-medical compatible self bias opamp in 45nm CMOS technology

In this paper a low power, high gain self bias opamp suitable for biomedical applications has been described. A novel trans conductance boosting technique is introduced without having any additional power consumption. A simple technique of biasing the opamp has been introduced for very low offset and without having any requirement for external reference circuit. A prototype of two stage amplifier design presented to verify the proposed technique and described its robustness across PVT variations by showing simulation results. The design is implemented in 45nm CMOS technology and simulated with Spectre. Simulation results show that the proposed opamp exhibits FOM of 625 and 2 times better than state of art. The circuit consumes 26uW from 1.5V supply and occupying 0.00282mm2 silicon area.