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 and the output referred power spectral density is -126 dBm/Hz. The device has good linearity, with a maximum gain error of ±0.5 dB and a dynamic range of 60 dB.