DESCRIPTION

· The AD8320 is a digitally controlled variable gain amplifier optimized for coaxial line driving applications.

· It uses an 8-bit serial word to determine the desired output gain over a 36 dB range (256 gain levels).

· The device consists of a digitally controlled variable attenuator (0 dB to -36 dB), a low noise fixed gain buffer, and a low distortion high power amplifier.

· It has a 220 Ω input impedance and accepts a single-ended input signal up to 0.310 V p-p.

· The output is specified for driving a 75Ω load, such as coaxial cable, but can drive other loads.

· It maintains a constant 75 Ω output impedance during power-up and power-down, eliminating the need for external 75 Ω back-termination.

· The AD8320 operates from a single +5 V to +12 V supply and has an operational temperature range of -40 °C to +85 °C.

FEATURES

· 8-Bit Serial Gain Control with V/V/LSB Linear Gain Response.

· 36 dB Gain Range with 60.20 dB Gain Accuracy.

· Upper Bandwidth: 150 MHz.

· 22 dBm 1 dB Compression Point (75 V).

· Drives low distortion signals into 75 V load: -57 dBc SFDR at 42 MHz and 12 dBm Out, -46 dBc SFDR at 42 MHz and 18 dBm Out.

· Single Supply Operation from 5 V to 12 V.

· Maintains 75 V Output Impedance during Power-Up and Power-Down.

· Supports SPI Input Control Standard.

APPLICATIONS

· Coaxial Cable Driver.

· HFC Cable Telephony Systems.

· HFC High Speed Data Modems.

· Interactive Set-Top Boxes.

· PC Plug-In Modems.

· Interfaces with AD9853 I2C Controlled Digital Modulator.

· High Performance Digitally Controlled Variable Gain Block.