This document describes the features of Analog Devices' AD8331/AD8332/AD8334 series ultralow noise variable gain amplifiers (VGAs) with preamplifier. The features include ultralow noise, wide gain range, low power consumption, and applications such as ultrasound and sonar time-gain controls, high performance automatic gain control systems, and I/Q signal processing.
The AD8331/AD8332/AD8334 family provides ultralow‑noise preamplifiers and programmable gain stages optimized for ultrasound, sonar, and high‑speed ADC applications. Each device integrates a low‑noise LNA, a linear‑in‑dB VGA, and a selectable post‑amplifier with output clamping.
The document includes full electrical specifications, absolute maximum ratings, pin‑out tables, typical performance curves, measurement considerations, and an ordering guide with package options for each part number.
| Voltage noise | 0.74 nV/√Hz |
|---|---|
| Current noise | 2.5 pA/√Hz |
| 3 dB bandwidth (AD8331) | 120 MHz |
| 3 dB bandwidth (AD8332/AD8334) | 100 MHz |
| Low power consumption (AD8331) | 125 mW/channel |
| Gain range (LO mode) | -4.5 dB to +43.5 dB |
| Gain range (HI mode) | 7.5 dB to 55.5 dB |
| Operating temperature range | ‑40 °C to +85 °C |
The devices operate from –40 °C to +85 °C.
AD8334 is available in a 64‑lead Lead Frame Chip Scale Package (LFCSP).
The AD8331 exhibits a voltage‑noise density of 0.74 nV/√Hz.
The AD8332 consumes about 145 mW per channel.