04/2011

ARA2004

Address-Programmable Reverse

Amplifier with Step Attenuator

Data Sheet - Rev 2.2

feAtuRes

• Low cost integrated amplifier with Step

Attenuator

• Attenuation Range: 0 - 59 dB, adjustable in

1 dB increments via a 3-wire Serial Control

• Meets DOCSIS distortion requirements at a +60

dBmV output signal level

• Low distortion and low noise

• Frequency range: 5 - 100 MHz

• 5 Volt Operation

• -40 to +85 8C temperature range

• RoHS Compliant Package Option

ApplicAtions

• MCNS/DOCSIS Compliant Cable Modems

• CATV Interactive Set-Top Box

Telephony over Cable Systems

•

OpenCable Set-Top Box

•

Residential Gateway

•

pRoDuct DescRiption

The ARA2004 is designed to provide 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. This

device uses a balanced circuit design that exceeds the

MCNS/DOCSIS requirement for harmonic performance

s12 package

28-pin ssop

with Heat slug

figure 1: functional Block Diagram for Docsis 3.0 Application

at a +60 dBmV output level while only requiring a single

polarity +5 V supply. Both the input and output are

matched to 75 ohms with an appropriate transformer.

The precision attenuator provides up to 58 dB of

attenuation in 1 dB increments via a three-wire serial

interface. With external passive components, this

device meets IEC 1000-4-12 and ANSI/IEEE C62.41-

1991 100KHz ringwave tests, as well as IEC1000-4-5

1.2/50 µS surge tests. The ARA2004 is offered in a

28-pin SSOP package featuring a heat slug on the

bottom of the package.

Diplexer

ARA2000

SAW

Filter

Double-

Conversion

Tuner

MAC

Upstream

QPSK/16QAM

Modulator

QAM Receiver

with FEC

Balun

Low Pass

Filter

Transmit Enable/Disable

Enable

Data

Clock

Address Control

2

Microcontroller

with Ethernet

MAC

RAM

ROM

10Base-T

Transceiver

RJ45

Connector

Clock

Clock

Data

Data

54-860 MHz

44 MHz

5-42 MHz