A new ELIN lossy integrator with instantaneous "arcsinh" companding

In this paper a new ELIN lossy integrator with instantaneous "arcsinh" companding as a basic building block for active filter design is investigated. It is shown that "sinh" and "arctanh" functions can be used in ELIN systems to obtain "arcsinh" and "tanh" companding, respectively. The circuit has been obtained using the state-space synthesis and is composed of "tanh" and "sinh" blocks which can be implemented in bipolar technology. The main advantages of the proposed structure are: for "arcsinh" companding there is no need for biasing in order to ensure only positive signals; instantaneous companding is useful to reduce the voltages and thus enlarge the dynamic range; the linearity of the proposed structure depends on the accuracy in which the range of the "sinh" transfer characteristics is valid. The proposed circuit has been simulated for a 0.8/spl mu/m BiCMOS technology showing remarkable good performances, and proving the practical applicability of the proposed structure.