The AD8331/AD8332 are single- and dual-channel ultralow noise, linear-in-dB, variable gain amplifiers. Although optimized for ultrasound systems, they are usable as low noise variable amplifiers.
The AD8331 (single‑channel) and AD8332 (dual‑channel) are ultralow‑noise variable‑gain amplifiers (VGAs) that integrate a low‑noise preamplifier (LNA). Each channel provides a programmable gain range, selectable output clamping, and active input‑impedance matching, all powered from a single 5 V supply.
These devices are optimized for high‑performance ADC drivers, ultrasound and sonar time‑gain control, and other high‑speed signal‑processing applications. They are offered in space‑saving packages: AD8331 in a 20‑lead QSOP, AD8332 in 28‑lead TSSOP or 32‑lead LFCSP, and operate from –40 °C to +85 °C.
| Voltage noise | 0.74 nV/√Hz |
|---|---|
| Current noise | 2.5 pA/√Hz |
| 3 dB bandwidth | 120 MHz |
| Power consumption | 125 mW per channel |
| Gain range (LO) | -4.5 dB to +43.5 dB |
| Gain range (HI) | +7.5 dB to +55.5 dB |
| Output‑referred noise | 48 nV/√Hz (typical) |
| Supply voltage | Single 5 V |
| Operating temperature range | -40 °C to +85 °C |
| Package options | AD8331: 20‑lead QSOP; AD8332: 28‑lead TSSOP, 32‑lead LFCSP |
Both devices operate from a single 5 V supply.
They are rated for –40 °C to +85 °C.
The voltage noise is 0.74 nV/√Hz.
LO gain ranges from –4.5 dB to +43.5 dB, while HI gain ranges from +7.5 dB to +55.5 dB.