A new differential ELIN low pass filter of “Sinh” type in bipolar technology

In this paper a new differential externally linear/internally nonlinear (DELIN) low pass filter (LPF) of “sinh” type in bipolar technology is presented. The DELIN systems provide a higher dynamic range and low noise, which represent important advantages for the implementation of active filters. The proposed structure provides instantaneous “arcsinh” companding on the internal nets, which minimize the voltage signals and maintain a performing dynamic range. The circuit proposed in this paper has been obtained using state-space synthesis and it is composed of differential nonlinear cells of “tanh” and “sinh/cosh” types. The simulations performed in a 0.18µm bipolar technology confirm the theoretical results.