Analytical synthesis of high-order single-ended-input OTA-grounded C all-pass and band-reject filter structures

The synthesis method based on the analytical solution of a single nth-order filter transfer function and the generation of n + 1 simple and realizable transfer functions implemented using lossless integrators and one additional constraint is applied to facilitate the development of new voltage-mode high-order operational transconductance amplifiers and capacitors (OTA-C) all-pass and band-reject filters. The presented nth-order all-pass and band-reject filters contain n + 2, i.e., at least n fewer OTAs and enjoy lower component spread than the recently published filter structures in addition to achieving three criteria: all single-ended-input OTAs, all grounded capacitors, and the least number of component counts, simultaneously. Furthermore, two different types of the synthesized filter structures, equal capacitance and equal transconductance, are suggested for easier IC manufacture and simpler biasing architecture, respectively. H-Spice simulations, using 0.25-mu m process and 1.25-V supply voltages, validate theoretical predictions.