Reconfigurable Ferroelectric Bandpass Filter With Low-Frequency Noise Analysis for Intracardiac Electrogram Monitoring

Implantable cardioverter defibrillators (ICDs) provide real-time monitoring and immediate defibrillation for life-threatening arrhythmias. However, the intracardiac electrogram (IEGM) acquisition of ICDs faces stringent constraints, including power consumption, low-frequency noise, and patient-specific physiological variability. This article introduces an ultralow-power, high-resolution, reconfigurable three-stage bandpass filter designed specifically for IEGM, utilizing ferroelectric field-effect transistor (FeFET) technology provided by a foundry platform. By employing adjustable threshold voltage $V {_{\text {th}}}$ and gate capacitance of FeFET as programmable pseudo-high-value resistors (PHVRs) and capacitor structures, the filter enables personalized cardiac signal isolation tailored to individual patient needs. In addition, this work incorporates, for the first time, a comprehensive low-frequency noise model covering the entire operational region of FeFET into circuit-level analysis. Based on GlobalFoundries (GF) 28-nm SLPe FeFET-enabled process, the proposed filter achieves a wide gain tuning range (17–77 dB) and a flexible bandwidth tuning range (0.5–19 Hz for low cutoff frequency and 23–138 Hz for high cutoff frequency), with an average power consumption of 257 nW and minimum 11- $\mu $ V resolution.