Compact Sub-Hertz OTA-C Filter Design with MOS Interface-Trap Charge Pump Academic Article uri icon


  • Single-ended and differential OTA configurations are biased with MOSFET interface-trap charge-pumping current generators to achieve very low transconductances for tunable sub-hertz OTA-C filter implementation. The paper reviews the basic physics of the current generator, presents the transconductor circuits, and two OTA-C filter configurations based on these transconductors. One of the filters is a lowpass with an experimentally determined lowest cutoff frequency of 0.18Hz, and the other is a fully differential band-pass with individually tunable lower and upper cut-off frequencies measured down to 0.3Hz. The former has one 15pF filter capacitor, and occupies an area of 0.0346 mm2, whereas the latter contains four such capacitors, and occupies an area of 0.188 mm2.

author list (cited authors)

  • Becker-Gómez, A., Çilingiroğlu, U., & Silva-Martinez, J.

citation count

  • 0

publication date

  • January 2002