ADRF6516 is a matched pair of fully differential, low noise and low distortion programmable filters and variable gain amplifier (VGA). Each channel is capable of rejecting large out-of-band interferers while reliably boosting the desired signal, thus reducing the bandwidth and resolution requirements on the analog-to-digital converters (ADCs). The excellent matching between channels and their high spurious-free dynamic range over all gain and bandwidth settings make the ADRF6516 ideal for quadrature-based (IQ) communication systems with dense constellations, multiple carriers, and nearby interferers.

The filters provide a six-pole butterworth response with 1dB corner frequencies programmable through the SPI port from 1MHz to 31MHz in 1MHz steps. The preamplifier that precedes the filters offers a SPI-programmable option of either 3dB or 6dB of gain. The preamplifier sets a differential input impedance of 1600ohms and has a common-mode voltage that defaults to VPS/2 but can be driven from 1.1V to 1.8V.

The variable gain amplifiers that follow the filters provide 50dB of continuous gain control with a slope of 15.5mV/dB. Their maximum gains can be programmed to various values through the SPI. The output buffers provide a differential output impedance of 30ohms and are capable of driving 2Vp-p into 1kohms loads. The output common-mode voltage defaults to VPS/2, but it can be adjusted down to 700mV by driving the high impedance VOCM pin. Independent, built-in dc offset compensation loops can be disabled if fully dc-coupled operation is desired. The high-pass corner frequency is defined by external capacitors on the OFS1 and OFS2 pins and the VGA gain.

It operates from a 3.15V to 3.45V supply and consumes a maximum supply current of 360mA when programmed to the highest bandwidth setting. When disabled, it consumes <9mA.