The AD6121 is a low power receiver IF subsystem specifically designed for CDMA applications. It consists of high dynamic range IF amplifiers with voltage controlled gain, a divide-by-two quadrature generator, an I and Q demodulator, and a powerdown control input. An integral low dropout regulator allows operation from battery voltages from 2.9 V to 4.2 V. The gain control input accepts an external gain control voltage input from a DAC. It provides 94.5 dB of gain control with a nominal 52.5 dB/V scale factor when using an internal voltage reference. The gain control interface reference input can be connected to either the internal reference or an external reference. The I and Q demodulator provides differential quadrature baseband outputs to interface with CDMA baseband converters. A divide-by-two quadrature generator followed by dual polyphase filters ensures maximum 2.5 quadrature accuracy.