The AD603ARZ is a Low Noise 90MHz Variable Gain Amplifier for use in RF and IF AGC systems. It provides accurate, pin-selectable gains of -11dB to +31dB with a bandwidth of 90MHz or +9dB to 51+dB with a bandwidth of 9MHz. Any intermediate gain range may be arranged using one external resistor. The input referred noise spectral density is only 1.3nV/√Hz and power consumption is 125mW at the recommended ±5V supplies. The decibel gain is linear in dB, accurately calibrated and stable over-temperature and supply. The gain is controlled at high impedance (50MR), low bias (200nA) differential input, the scaling is 25mV/dB, requiring a gain control voltage of only 1V to span the central 40dB of the gain range. An over range and under range of 1dB is provided whatever the selected range. The gain control response time is less than 1μs for a 40dB change. The differential gain control interface allows the use of either differential or single-ended positive or negative control voltages.
