A Continuous Time Level-Crossing ADC with Adaptive Sampling for Biomedical Application

Abstract

To reduce the power consumption of a bio-electrical signal detection system, a level-crossing analog-to-digital converter (LC-ADC) with low power consumption was proposed for biomedical signal detection. An adaptive resolution sampling mode is also designed to reduce power consumption on the original basis. The level-crossing ADC is designed and simulated using a 180-nm CMOS process. The measurement results show that the power consumption is only 197 nW, the effective number of bits is 6.4 bits and the signal-to-noise and distortion ratio is 41.6 dB under 0.8 V power supply voltage. The proposed LC-ADC uses a chip area of 0.147 mm² and the FOM is 278 fJ/conversion.