A 2.3 $\mu$ W ECG-On-Chip for Wireless Wearable Sensors

This brief presents an ultra-low power single chip solution for electrocardiography (ECG) signal acquisition and processing in wearable ECG sensors. The chip contains a low noise preamplifier with embedded band-pass function, a programmable gain buffer, a 12-bit successive approximation ADC, a novel morphological filter based QRS detector, 8-Kb on-chip SRAM, a control unit and MCU interfaces. The chip was designed and implemented in 0.35-μm standard CMOS process. The analog core operates from 0.8 V to 1.8 V, while the digital circuits and SRAM operate from 1.5 V to 3.6 V. The chip has a total core area of 5.74 mm
²
and consumes 2.3 μW. Small size and low power consumption make this chip suitable for usage in wearable ECG sensors. Apart from presenting the measurement results, we also successfully demonstrate a prototype wearable ECG device, for long term cardiac monitoring using the proposed ECG-on-chip.