AD8367ARUZ

The AD8367 is a high performance 45 dB variable gain amplifier with linear-in-dB gain control for use from low frequencies up to several hundred megahertz. The range, flatness, and accuracy of the gain response are achieved using Analog Devices’ X-AMP (infinity) architecture, the most recent in a series of powerful proprietary concepts for variable gain applications, which far surpasses what can be achieved using competing techniques. The input is applied to a 9-stage, 200 Ω resistive ladder network. Each stage has 5 dB of loss, giving a total attenuation of 45 dB. At maximum gain, the first tap is selected; at progressively lower gains, the tap moves smoothly and continuously toward higher attenuation values. The attenuator is followed by a 42.5 dB fixed gain feedback amplifier—essentially an operational amplifier with a gain bandwidth product of 100 GHz —and is very linear, even at high frequencies. The output third order intercept is +20 dBV at 100 MHz (+27 dBm, re 200 Ω), measured at an output level of 1 Vₚ₋ₚ with VS = 5 V.

Applications

• Cellular base stations
• Broadband access
• Power amplifier control loops
• Complete, linear IF AGC amplifiers
• High speed data I/O