ADL5331 is a high performance, voltage-controlled variable gain amplifier/attenuator for use in applications with frequencies up to 1.2GHz. 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 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 0V at a minimum gain to 1.4V at a full gain with a 40mV/dB scaling factor over most of the range.

The output of the high accuracy wideband attenuator is applied to a differential trans-impedance 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.

It consumes 240mA of current including the output pins and operates off a single supply ranging from 4.75V to 5.25V. A power-down function is provided by applying a logic low input on the ENBL pin.