The ADL5331 is a high performance, voltage-controlled variable 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 noise and minimizes distortion while it also reduces the risk of spurious feed-forward at low gains and high frequencies caused by parasitic coupling. The 50 Ω differential input system converts the applied differential voltage at INHI and INLO to a pair of differential currents 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 a full gain with a 40 mV/dB scaling factor over most of the range. The output of the high accuracy wideband attenuator is applied to a differential transimpedance output stage. The output stage provides 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 a logic low input on the ENBL pin. The current consumption in power-down mode is 250 μA. 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-free LFCSP 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 * Voltage-controlled amplifier/attenuator * Operating frequency: 1 MHz to 1.2 GHz * Optimized for controlling output power * High linearity: OIP3 47 dBm @ 100 MHz * Output noise floor: −149 dBm/Hz @ maximum gain * Input impedance: 50 Ω * Output impedance: 20 Ω * Wide gain-control range: 30 dB * Linear-in-dB gain control function: 40 mV/dB * Single-supply voltage: 4.75 V to 5.25 V