Reverse Amp Eyes Cable Modems And Interactive Set-Top Boxes

For use in cable modems and interactive set-top boxes, ARA1400 reverse amplifier with step attenuator delivers up to 33 dB gain at 5V and provides low distortion and output noise while conforming to MCNS/DOCSIS standards of the cable industry. An integrated, digitally-controlled precision step attenuator is used to increase signal output power to the required levels. The attenuator varies gain in 4 dB steps over a range of 56 dB to provide better performance than variable gain amplifiers. ARA1400 reverse amp also provides maximum output noise power of -41 dBmV in a 3.2 MHz bandwidth at minimum gain setting and a noise figure of 1.7 dB. And it demonstrates maximum second harmonic levels of -55 dBc and maximum third harmonics of -60 dBc. The single-ended design achieves its harmonic performance without the need for a balun on the output stage, further reducing design costs.