GENERAL DESCRIPTION

The AD605 is a low noise, accurate, dual-channel, linear-in-dB variable gain amplifier (VGA), optimized for any application requiring high performance, wide bandwidth variable gain control. Operating from a single 5 V supply, the AD605 provides differential inputs and unipolar gain control for ease of use. Added flexibility is achieved with a user-determined gain range and an external reference input that provide user-determined gain scaling (dB/V).

FEATURES

2 independent linear-in-dB channels

Input noise at maximum gain: 1.8 nV/√Hz, 2.7 pA/√Hz

Bandwidth: 40 MHz (–3 dB)

Differential input

Absolute gain range programmable

–14 dB to +34 dB (FBK shorted to OUT) through

0 dB to 48 dB (FBK open)

Variable gain scaling: 20 dB/V through 40 dB/V

Stable gain with temperature and supply variations

Single-ended unipolar gain control

Output common mode independently set

Power shutdown at lower end of gain control

Single 5 V supply

Low power: 90 mW/channel

Drives ADCs directly

APPLICATIONS

Ultrasound and sonar time-gain controls

High performance AGC systems

Signal measurement