A low power low voltage biomedical signal acquisition chip

Abstract

As one of the main focus in non-invasive medical diagnostic, portable medical instrument can benefit numerous patients through real-time monitoring. However such devices usually operate under battery power supply which means stringent requirements on the supply voltage and power consumption. Apart from that, the weak bio-signal requires the devices to have ultra low input-referred noise over a low frequency range. Electrochemical interface between human skin and electrode creates large DC offset components which add to the design challenges to reject DC offset. This thesis presents a 1.5V 4uW ECG signal acquisition IC with 1.8uVrms input-referred noise. The system includes a low noise instrumentation amplifier with DC offset rejection, and an 11 bit successive approximation ADC.