The AD604 is a dual-channel, ultralow noise variable gain amplifier with an absolute gain range of 0 dB to 48 dB and an accuracy of ±1.0 dB. It features a 300 kΩ input impedance and a 40 MHz bandwidth.
The AD604 is a dual, ultralow‑noise variable gain amplifier (VGA) optimized for time‑gain control in ultrasound and sonar applications, but suitable for any low‑noise, wide‑bandwidth gain‑control need. Each channel offers 300 kΩ input resistance, unipolar gain control, and programmable gain from 0 dB to 48 dB (or 6 dB to 54 dB with a 20 dB preamplifier).
The document provides full specifications, absolute maximum ratings, pin configuration, typical performance curves, and a functional block diagram. It also lists available packages (24‑lead SSOP, SOIC, PDIP) and operating temperature range (‑40 °C to +85 °C).
| Input Resistance | 300 kΩ |
|---|---|
| Input Capacitance | 8.5 pF |
| Input Bias Current | ‑27 µA |
| Input Voltage Noise (14 dB gain) | 0.8 nV/√Hz |
| Input Current Noise | 3.0 pA/√Hz |
| -3 dB Bandwidth | 40 MHz |
| Power Supply Voltage | +5 V |
| Power Dissipation (full channel) | 220 mW |
| Quiescent Supply Current | 32 mA |
| Operating Temperature Range | ‑40 °C to +85 °C |
Each channel has an input resistance of 300 kΩ.
Gain is set by the voltage on the VGN pin; a positive voltage increases gain, and grounding the pin powers down the channel.
The AD604 provides a –3 dB bandwidth of 40 MHz across its gain range.
The AD604 is offered in 24‑lead SSOP, SOIC, and PDIP packages.