OTA-C simulation of passive filters via embedding

A general method for operational transconductance amplifier (OTA)-C filter synthesis is presented. Given any passive RLC network, several economical active structures can be obtained from it, all retaining the passive sensitivities of the original network. By following simple design rules, the sensitivities to the OTAs' transconductances can also be maintained at low level. The structures obtained can be made to present all the capacitors grounded, and the effect of parasitic circuit elements can be easily predicted by looking for the equivalents in the prototype. The filters are fully tunable and so can be used in conjunction with automatic tuning techniques to realize precise, fully integrated continuous-time filters.<>