High-Accuracy ECG Signal Acquisition Using a Power-Efficient 6-bit Level-Crossing ADC

This paper presents a novel approach using level-crossing ADCs (LC-ADCs), which provide a more power-efficient solution by sampling only when the input signal exceeds predefined amplitude thresholds. A 6-bit LC-ADC architecture that eliminates the need for an n-bit DAC and uses a single comparator, incorporating integrated sample-and-hold and logic functions, is proposed. This design drastically reduces power consumption while maintaining accuracy, making it particularly suitable for low-power biomedical applications. Simulation results in 180 nm CMOS technology with 1.8-V power supply demonstrate the system’s high performance, including a Figure-of-Merit (FoM) that outperforms traditional designs. The proposed LC-ADC architecture is shown to be highly efficient, with significant reductions in power usage and FoM to 90 nW and 0.115fJ/step, offering an ideal solution for long-term, energy-constrained biomedical signal monitoring.