Design and analysis of low noise, low power OTA considering design trade-offs for biomedical applications

• Innovative OTAs designed for biomedical applications. • Enhances efficiency with low power and high signal fidelity. • PMOS CVF OTA excels in noise and power optimization. • Class AB FVF OTA achieves best gain and bandwidth. Optimized for wearable and biomedical devices such as EEG-based seizure detection systems. This paper details the design and implementation of four different OTAs optimized for low noise, low power consumption and high signal fidelity. The following four OTAs—NMOS Conventional Voltage Follower OTA, PMOS Conventional Voltage Follower OTA, NMOS Flipped Voltage Follower OTA, and NMOS Class AB Flipped Voltage Follower OTA, have been designed, simulated, and analyzed for performance comparison, considering applications in Biomedical Front-End circuits. These designs, when simulated in UMC 180 nm, achieve gain between 61 dB and 78.86 dB, -3 dB bandwidth ranging from 49.277 kHz to 65.01 kHz, and phase margins between 45 deg to 60 deg approximately. The lowest input noise recorded is by PMOS CVF OTA which is 0.665 µV/√Hz, and the best power consumption is found to be 128 nW having layout dimensions of 32.7 µm × 28.8 µm, resulting in a total area of 941.76 µm² with a layout density of 0.321246. thus, making the OTA highly suitable for biomedical applications. Thus, the OTAs demonstrate significant improvements in noise performance, and power consumption, with a compact layout, making them highly suitable for integration to energy efficient and implantable biomedical front-end circuits.