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, gain accuracy typical is ±0.5 dB. The AD603 is constructed using bipolar input transistors, providing low input bias current for high precision gain control. It also has a low supply voltage and low power consumption, making it an ideal choice for RF and IF AGC applications.