Gainversionsensitivity product-a figure of merit for hybrid-integrated filters using single operational amplifiers

It is shown that a different measure of performance must be used to evaluate hybrid-integrated active filters than has been used to evaluate active filters in discrete form. Where sensitivity was previously found to be an adequate and useful measure for Q-switching-switchingswitched stability of discrete active filters; the gainversionsensitivity product gives an accurate measure of Q-switching-switchingswitched stability forhybrid-integrated circuits. Where negative feedback filter schemes were found to be preferable with respect to Q-switching-switchingswitched stability when realized in discrete form, positive feedback, schemes, with their very much lower gainversionsensitivity product may be preferable in hybrid-integrated filter circuits. In addition, they require low-gain amplifiers that can be used up to higher frequencies. Q-switching-switchingswitched-stability measurements of hybrid-integrated positive feedback, or Sallen-Key-type circuits, which were realized with tantalum thinversionfilm resistors and capacitors combined with beamplasmaleaded operational amplifier chips have been shown to agree very accurately with the predictions derived from gainversionsensitivity calculations.