Design and Analysis of a Low-Power Two-Stage Miller-Compensated OTA in 45 nm Technology for ECG Signal Acquisition

This paper presents the design, simulation, and analysis of a two-stage Miller-compensated operational transconductance amplifier (OTA) using 45 nm process technology in a cadence environment for an analog front-end circuit required for ECG signal acquisition. The OTA, an essential component in the analog front-end circuits used in sensor interface circuits, is designed to achieve high gain, wide output swing, good transient and frequency response, and improved stability. The OTA design is based on various specifications, including power supply voltage, gain-bandwidth product (GBW), slew rate (SR), phase margin (PM), and incremental common mode ranges (ICMR+ and ICMR-). Detailed AC, transient, and stability analyses are conducted to optimize the circuit for application in preamplification stages, particularly for ECG signal acquisition. The OTA design utilizes a cadence simulation framework, with special consideration for minimizing the circuit size to integrate into compact wearable devices. The proposed design demonstrates promising results, offering a potential solution for low-power, high-performance signal amplification in ECG signal acquisition.