Structure generation and performance comparison of canonical elliptic Gm-C filters

In the paper an explicit, matrix description based procedure of generating canonical structures of low-pass elliptic filters with grounded and floating capacitors is given. A detailed comparison of third order leap-frog and inverse follow-the-leader structures is carried out. The major attention is focused on the sensitivity performance of the filters in question. Design guidelines that follow from the presented results are also given. It follows that filters containing floating capacitors can be viewed as an interesting alternative to the filters containing grounded capacitors only. Such filters exhibit good sensitivity performance, they have a smaller number of active elements and can be realized with all transconductances equal, which is important for integrated circuit implementations.