ADL5331-EVALZ

The ADL5331 is a high performance, voltage-controlledvariable gain amplifier/attenuator for use in applications with frequencies up to 1.2 GHz. The balanced structure of the signal path maximizes signal swing, eliminates common-mode noiseand minimizes distortion while it also reduces the risk of spurious feed-forward at low gains and high frequencies caused by parasitic coupling. The 50 ? differential input system converts the applieddifferential voltage at INHI and INLO to a pair of differentialcurrents with high linearity and good common-mode rejection. The signal currents are then applied to a proprietary voltage-controlled attenuator providing precise definition of the overall gain under the control of the linear-in-dB interface. The GAIN pin accepts a voltage from 0 V at a minimum gain to 1.4 V at afull gain with a 40 mV/dB scaling factor over most of the range.The output of the high accuracy wideband attenuator is appliedto a differential transimpedance output stage. The output stageprovides a differential output at OPHI and OPLO, which must be pulled up to the supply with RF chokes or a center-tapped balun.The ADL5331 consumes 240 mA of current including the output pins and operates off a single supply ranging from 4.75 V to 5.25 V. A power-down function is provided by applying alogic low input on the ENBL pin. The current consumption inpower-down mode is 250 ?A.The ADL5331 is fabricated on an Analog Devices, Inc., proprietary high performance, complementary bipolar IC process.The ADL5331 is available in a 24-lead (4 mm ? 4 mm), Pb-freeLFCSP package and is specified for operation from ambient temperatures of ?40?C to +85?C. An evaluation board is also available.Applications Transmit and receive power control at RF and IF CATV distribution