Current-mode filters using syllabic companding

We discuss current-input current-output signal processors, the voltage state variables of which have a compressed dynamic range thanks to syllabic companding. In this way, for a wide variation of input signals, the internal signals stay well above noise, while at the same time remaining below overload levels. This results in larger dynamic range in comparison to linear processors with the same power dissipation. Theoretical, simulation, and experimental results are given. The circuits presented are an illustration of a general technique for developing nonlinear circuits which are input-output linear.

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