A Fully-Integrated Two-Channel A/D Interface for the Acquisition of Cardiac Signals in Implantable Pacemakers

This work presents an input stage for a cardiac pacemaker fully integrated in 0.35-\u3bcm CMOS technology. The system can acquire and digitize to 8 bits both atrial and ventricular electrical activity. Log-domain circuits are exploited to amplify and filter the input signal, while \u3a3\u394 modulation is exploited to convert it. The design is power optimized, indeed the current consumption is limited to 2.9 \u3bcA, while the power supply ranges from 2.8 to 1.8 V. The total area is 2.2 mm2 and experimental data prove correct filtering and a total dynamic range of at least 47 dB