Programmable Switched-Capacitor Filter Design Tool for Biomedical Signal Acquisition


Kaya K., OZANOĞLU K., Kahya Y. P., DÜNDAR G.

19th International Conference on Synthesis, Modeling, Analysis and Simulation Methods, and Applications to Circuit Design, SMACD 2023, Funchal, Portekiz, 3 - 05 Temmuz 2023, (Tam Metin Bildiri) identifier identifier

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Doi Numarası: 10.1109/smacd58065.2023.10192182
  • Basıldığı Şehir: Funchal
  • Basıldığı Ülke: Portekiz
  • Anahtar Kelimeler: active filters, auscultation, biomedical, CAD, cardiac, switched-capacitor
  • Boğaziçi Üniversitesi Adresli: Evet

Özet

This paper presents an open source design support tool for a respiratory and cardiac signal acquisition system that utilizes programmable switched-capacitor analog filters in the analog front end. The proposed filter topologies are based on cascaded second-order-section filters and are designed to be programmable in terms of the cut-off frequency via the switching frequency. The design support tool is written in Python and is capable of calculating the capacitance ratios for a given second-order filter topology, generating a parameter file, and performing periodic AC simulations of the designed circuit in SpectreRF. The tool uses a simple estimation algorithm to find the best possible integer fit with an error cost function. Two sets of 6th-order switched-capacitor filter sets are designed using biquadratic sections in 180nm CMOS process. The proposed design methodology offers a better area fraction reduction compared to simple integer ratio designs. Post-layout simulation results demonstrate the effectiveness and efficiency of the proposed design support tool for switched-capacitor analog filters in respiratory and cardiac signal acquisition systems.