A low-power high-linearity CMOS baseband filter for wideband CDMA applications

In this paper, the design and performance of a CMOS fifth-order low-pass anti-aliasing filter for baseband mobile communication are presented. Based on a differential difference amplifier (DDA), a novel fully-differential Sallen-Key filter is realized. This fifth-order filter operates at a supply voltage of 3 V and has a cutoff frequency of 19 MHz. It provides up to 1 V differential output with 0.03% total harmonic distortion (THD) and dissipates only 4.5 mW. The input IP3 is +39 dBm, and the input-referred noise in the passband is 60 nV//spl radic/(Hz).