The AD8323 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 53.5 dB range resulting in gain changes of 0.7526 dB/LSB. The AD8323 comprises a digitally controlled variable attenuator of 0 dB to –53.5 dB, which is preceded by a low noise, fixed gain buffer and is followed by a low distortion high power amplifier. The AD8323 accepts a differential or single-ended input signal. The output is specified for driving a 75 Ω load, such as coaxial cable.