AD604 Rev. G is a dual-channel ultralow noise variable gain amplifier with extremely low input noise and programmable gain range. It is suitable for applications such as ultrasound and sonar time-gain controls, high-performance AGC systems, and signal measurement.
The AD604 is a dual‑channel, ultralow‑noise, linear‑in‑dB variable gain amplifier (VGA) optimized for time‑based gain control in ultrasound applications, but also suitable for AGC systems and signal measurement. Each channel provides 300 kΩ input resistance, unipolar gain control, and programmable gain ranges from 0 dB to 48 dB (or 6 dB to 54 dB with a 20 dB preamplifier).
Key features include an input‑referred noise of 0.8 nV/√Hz (14 dB preamp), a constant –3 dB bandwidth of 40 MHz, gain scaling up to 40 dB/V, and a gain‑control interface that powers down the channel when the control voltage is below 50 mV. The device is offered in 24‑lead SSOP, SOIC, and PDIP packages and operates from –40 °C to +85 °C.
| Input Resistance | 300 kΩ |
|---|---|
| Input Capacitance | 8.5 pF |
| Input Bias Current | –27 mA |
| Input Voltage Noise (14 dB preamp) | 0.8 nV/√Hz |
| Input Current Noise | 3.0 pA/√Hz |
| –3 dB Bandwidth | 40 MHz |
| Slew Rate | 170 V/µs |
| Output Impedance (10 MHz) | 2 Ω |
| Power Supply Voltage | +5 V |
| Quiescent Supply Current (full channel) | 32‑36 mA |
| Power Dissipation (full channel) | 220 mW |
Each channel has an input resistance of 300 kΩ.
The device provides a constant –3 dB bandwidth of 40 MHz across its gain range.