The AD603 is a low noise, voltage controlled amplifier for use in RF and IF AGC systems. It provides accurate, pin-selectable gains of −11 dB to +31 dB with a bandwidth of 90 MHz or +9 dB to 51+ dB with a bandwidth of 9 MHz. Any intermediate gain range may be arranged using one external resistor. The input referred noise spectral density is only 1.3 nV/√Hz, lower than any other similar product.
The AD603 is a low‑noise, voltage‑controlled amplifier designed for RF and IF AGC systems. It offers linear‑in‑dB gain control, pin‑programmable gain ranges, and a high‑impedance gain‑control interface that requires only a 1 V control voltage for a 40 dB span.
The datasheet provides detailed specifications, absolute maximum ratings, pin descriptions, typical performance curves, and application notes such as cascade operation, sequential and parallel gain‑control modes, and low‑ripple operation. Ordering information and package dimensions are also included.
| Input Resistance | 100 Ω (typical) |
|---|---|
| Gain Range | –11 dB to +31 dB (90 MHz BW) or –9 dB to +51 dB (9 MHz BW) |
| Power Consumption | 125 mW at ±5 V supplies |
| Supply Voltage (operating) | ±5 V |
| Maximum Output Swing | ±2.5 V into 500 Ω load |
| Gain Control Scaling | 25 mV/dB |
| Operating Temperature Range (AD603A) | –40 °C to +85 °C |
The gain control voltage ranges from –0.5 V to +0.5 V.
The absolute maximum supply voltage is ±7.5 V.
The gain‑control response time is less than 1 µs for a 40 dB change.