Analog baseband IC for use in direct conversion W-CDMA receivers

A 0.6 /spl mu/m BiCMOS analog baseband IC that enables a direct conversion W-CDMA receiver is described. Two diversity I/Q channels provide 87 dB of voltage gain, controllable in 1-dB steps. A 2 MHz low pass filter, synchronized to an external RC network, provides an accurate rejection mechanism against adjacent channel interference. A log amp provides a "Fast-RSSI" function for rapidly selecting gain settings. Low DC current (<5 mA/path), low input noise (<4 nV/Hz/sup 1/2/), and a high P3dB (-20 dBVrms) are achieved.