A 3/sup rd/-order elliptic syllabic-companding tanh filter

This paper presents a systematic design of a syllabic-companding, 3/sup rd/-order elliptic filter based on the nonlinear hyperbolic tangent function. The proposed filter, which includes a new current-mode peak detector, is realised by using a 0.8 /spl mu/m BiCMOS technology. Circuit simulation shows that the filter can achieve a maximum input dynamic range of 81.5 dB, while draining 0.8 mA quiescent current from a3 V power supply voltage.