A Biomedical Sensor Interface With A Sinc Filter And Interference Cancelation

A compact, low-power, digitally-assisted sensor interface for biomedical applications is implemented in a 0.18µm CMOS process. It exploits oversampling and digital design to reduce system area and power, while making the system more robust to interferers. Anti-aliasing is achieved using a charge-sampling filter with a sinc frequency response and programmable gain. A mixed-signal feedback loop creates a sharp, programmable notch for interference cancelation. The on-chip blocks operate from a 1.5V supply and consume between 255nW and 2.5µW depending on noise and bandwidth requirements.