Mixed-Signal IC With Pulse Width ModulationWireless Telemetry for Implantable CardiacPacemakers in 0.18-<i>μ</i>m CMOS

A low-power mixed-signal IC for implantable pacemakers is presented. The proposed system features three independent intracardiac signal readout channels with pulse-width-modulated outputs. Also, the proposed system is capable of measuring the amplitude and phase of the bioimpedance with pulse-width-modulated outputs for use in rate adaptive pacemakers. Moreover, a stimulation system is embedded, offering 16 different amplitudes from 1 to 7.8&amp;#x00A0;V. A backscattering transmitter transfers the output signals outside the body with very little power consumption. The proposed low-power mixed-signal IC is fabricated in a 0.18-&amp;#x03BC;m HV CMOS process and occupies 2.38 mm2. The biopotential channels extract the heart signals with 9.2 effective number of bits and the bioimpedance channels measure the amplitude and phase of the heart impedance with 1.35 &amp;#x03A9;&lt;formula&gt;&lt;tex&gt;$_{rms}$&lt;/tex&gt;&lt;/formula&gt; accuracy. The complete IC consumes only 4.2&amp;#x00A0;&amp;#x03BC;A from a 1-V power supply.Accepted Author ManuscriptBio-Electronic