this paper (see Theory section) can be restated in the CNN framework [25] as well. The model has to be altered to the hardwarefriendly full-range model [26] using nonlinear feedback templates. Nevertheless the CNN framework is defined on a discrete grid and therefore limited in its applications. Various CMOS VLSI implementations of CNNs have been reported [27]. They can be discriminated by fixed [28] or variable [29, 30] templates, current [26] or voltage mode [31], full [32] or limited [33] CNN-model, on-chip [34] or o#-chip sensors. They are referenced here in detail as a starting point for further investigations in the field of analog VLSI systems for signal processing.