DESCRIPTION

The ARA05050 is a GaAs IC designed to perform the reverse path amplification and output level control functions in a CATV Set-Top Box or Cable Modem. It incorporates a digitally controlled precision step attenuator that is preceded by an ultra low noise amplifier stage, and followed by an ultra-linear output driver amplifier. It is capable of meeting the MCNS/DOCSIS harmonic distortion specifications while only requiring a single polarity +5V supply. This part is a single ended design that does not require an output balun to achieve -55 dBc 2nd harmonic performance at +58 dBmV output levels. Both the input and output are matched to 75 ohms. The precision attenuator provides up to 30 dB of attenuation in 2 dB increments. The ARA05050 is supplied in a 28-pin SSOP package featuring a thermal heat slug on the bottom of the package. Soldering this heat slug to the ground plane of the PC board ensures the lowest possible thermal resistance for the device resulting in a long MTF.

FEATURES

• Integrated monolithic GaAs amplifier and step attenuator.

• Compatible with all digital and analog modulation types.

• Frequency range: 5 - 100 MHz.

• Gain: 0 - 30 dB, variable in 2 dB steps.

• 5 Volt operation.

• Low noise figure.

• Low distortion.

• Amplifier shutdown capability.

• Low cost.

• High reliability.

• Low signal to noise ratio at all gain levels.