ADRF6520 Datasheet | Analog Devices

FEATURES Matched VGAs and programmable filters Maximum gain: 53 d B Continuous gain control range: 60 d B Filter bypass mode I/Q bandwidth ±1 d B gain flatness: >1250 MHz 4-pole Butterworth filter I/Q bandwidth: 36 MHz to 720 MHz RMS detector IMD3: <- 55 d Bc for 1.5 V p-p posite output HD2, HD3: <- 55 d Bc for 1.5 V p-p output Noise figure: 10.5 d B at maximum gain NF < 11 d B over 12 d B of VGA2 gain backoff 100 Ω differential input, low impedance output Optional dc output offset correction SPI-programmable filter corners Single 3.3 V supply operation with power-down feature APPLICATIONS Point-to-point and point-to-multipoint radios Baseband IQ receivers Diversity receivers ADC drivers Instrumentation Medical GENERAL DESCRIPTION The ADRF6520 is a matched pair of fully differential low noise and low distortion programmable filters and variable gain amplifiers (VGAs). Each channel is capable of rejecting large, out of band interferers while reliably boosting the wanted signal, thus reducing the bandwidth and resolution requirements on the analog-todigital converters (ADCs). The excellent matching between channels and their high spurious-free dynamic range over all gain and bandwidth settings make the ADRF6520 ideal for quadrature-based (IQ) munication systems with dense constellations, multiple carriers, and nearby interferers. The filter corners, enable, and dc offset correction loop enable are all programmable via a serial peripheral interface (SPI). The first VGA that precedes the filters offers 30 d B of continuous gain control with a maximum gain of 18 d B and sets a differential input impedance of 100 Ω. The filters provide a four-pole Butterworth response with - 1 d B corner frequencies: 36 MHz, 72 MHz, 144 MHz, 288 MHz, 432 MHz, 576 MHz, and 720 MHz. For operation beyond 720 MHz, the filter can be disabled and pletely bypassed, thereby extending the - 1 d B bandwidth FUNCTIONAL BLOCK DIAGRAM 32 CS 31 VPSD 30 D 29 VPS 28 VPS 27 26 CHP1 25 ENBL INP1 1 INM1 2 3 CFLT1 4...