Design of Configurable gm−C Biquadratic Filter

Abstract

Design methodology of a voltage-mode programmable biquadratic filter using minimum components is proposed in this paper. Multifunction second-order filter has been implemented using two first-order filter sections. The proposed biquadratic filter has been realized with operational transconductance amplifier (OTA). Cut-off frequency and [Formula: see text]-factor of the biquadratic are controlled by the transconductance of the OTAs. The proposed design technique keeps all the sensitivities to lower values. The biquadratic filter operates at high frequency. The proposed structure is transformed into a third-order multifunction filter by adding minimum component, a single capacitor. Design of higher order filter using the proposed second-order function also has been investigated. The proposed synthesis is validated with SPICE simulation in 0.13[Formula: see text][Formula: see text]m technology. Total harmonic distortion, output noise, corner simulations, Monte Carlo analysis due to the circuit parameter and process parameter variation have been studied.

CMOS Design of Chaotic Systems Using Biquadratic OTA-C Filters

“…Some related works on OTA-C filters are the following: the authors in [20] show two new first-order universal active filter configurations employing OTAs and grounded capacitors; in [21], the authors present a biquadratic filter using one dual-output OTA, three single-output OTAs, and two grounded capacitors to derive a new quadrature oscillator with independent control of the oscillation frequency and the oscillation condition; the authors in [22] present an independently tunable five-input and three-output biquadratic filter using five single-ended output OTAs and two grounded capacitors; and the authors in [23] present an OTA-C filter for biomedical applications that consists of a cascade of biquadratic sections, each configured via a serial-peripheral-interface circuit embedded with nonvolatile memories to provide low-pass or bandpass response. An implementation of an OTA-C filter using commercially available discrete components was given in [24]; an OTA-based filter with low sensitivity operating at high frequency was given in [25]; OTAbased biquadratic filters with electronically reconfigurable transfer functions were given in [26]; and biquadratic OTA-C and universal filters with tunable pole-Q were introduced in [27]. One can find more works related to OTA-C filters, but in all cases, the topologies are quite similar to the ones given in the tutorial [28].…”