Variable Gain Amplifier Extends Frequency Out To 500

Said to be the industry's first wideband variable gain amplifier (VGA) to integrate an on-chip square law detector, the AD8367 is designed for use within a receive path AGC loop in cellular base station equipment. The device provides a flat gain response up to 500 MHz, covering all common intermediate frequencies found within GSM/CDMA/PCS and 3G equipment. It also provides 45 dB of "linear-in-dB" gain control adjustable through a single external control voltage of 0 to 1V, giving the design engineer 22 mV/dB output voltage scaling. Other key specifications include low noise (8 dB noise figure) and a highly linear output stage (+28 dBm output third order intecept). The on-chip square law detector enables the user to implement a single-chip automatic gain control (AGC) solution. In the AGC mode of operation, the amplifier provides the received signal strength indication (RSSI) output voltage and a constant fixed output level. Pricing is $4.55 each/1,000. ANALOG DEVICES, Norwood, MA. (781) 329-4700.