AD8370

Data Sheet FEATURES Programmable low and high gain (<2 dB resolution) Low range: −11 dB to +17 dB High range: 6 dB to 34 dB Differential input and output 200 Ω differential input 100 Ω differential output 7 dB noise figure @ maximum gain Two-tone IP3 of 35 dBm @ 70 MHz −3 dB bandwidth of 750 MHz 40 dB precision gain range Serial 8-bit digital interface Wide input dynamic range Power-down feature Single 3 V to 5 V supply APPLICATIONS Differential ADC drivers IF sampling receivers RF/IF gain stages Cable and video applications SAW filter interfacing Single-ended-to-differential conversion GENERAL DESCRIPTION The AD8370 is a low cost, digitally controlled, variable gain amplifier (VGA) that provides precision gain control, high IP3, and low noise figure. The excellent distortion performance and wide bandwidth make the AD8370 a suitable gain control device for modern receiver designs. For wide input, dynamic range applications, the AD8370 provides two input ranges: high gain mode and low gain mode. A vernier, 7-bit, transconductance (gm) stage provides 28 dB of gain range at better than 2 dB resolution and 22 dB of gain range at better than 1 dB resolution. A second gain range, 17 dB higher than the first, can be selected to provide improved noise performance. The AD8370 is powered on by applying the appropriate logic level to the PWUP pin. When powered down, the AD8370 consumes less than 4 mA and offers excellent input to output isolation. The gain setting is preserved when oper...