
Analog Devices
GENERAL DESCRIPTION
The AD8326 is a high-output power, digitally controlled, variable gain amplifier optimized for coaxial line driving applications such as data and telephony cable modems that are designed to the MCNS-DOCSIS upstream standard. An 8-bit serial word determines the desired output gain over a 53.5 dB range resulting in gain changes of 0.75 dB/LSB. The AD8326 is offered in two models, each optimized to support the desired output power and resulting performance.
FEATURES
Supports DOCSIS Standard for Reverse Path
Transmission
Gain Programmable in 0.75 dB Steps over a 53.5 dB Range
Low Distortion at 65 dBmV Output
–62 dBc SFDR at 21 MHz
–58 dBc SFDR at 65 MHz
1 dB Compression of 25 dBm at 10 MHz
Output Noise Level
–45 dBmV in 160 kHz
Maintains 75 Ω Output Impedance
Power-Up and Power-Down Condition
Upper Bandwidth: 100 MHz (Full Gain Range)
Single or Dual Supply Operation
APPLICATIONS
Gain-Programmable Line Driver
CATV Telephony Modems
CATV Terminal Devices
General-Purpose Digitally Controlled Variable Gain Block