5 V CATV Line Driver Coarse Step Output Power Control

The AD8327 is a low-cost, digitally controlled, variable gain amplifier optimized for coaxial line driving applications such as cable modems that are designed to the MCNS-DOCSIS upstream standard. An 8-bit serial word determines the desired output gain over a 48.16 dB range resulting in gain changes of 6.02 dB/major carry.

* Supports DOCSIS Standard for

Reverse Path Transmission

* Gain Programmable in 6.02 dB

Steps over a 48.16 dB Range

* Low Distortion at 60 dBmV Output

–63 dBc SFDR at 21 MHz

–57 dBc SFDR at 42 MHz

* Output Noise Level

–47 dBmV in 160 kHz