ARA2004 Datasheet, PDF (1/20 Pages) ANADIGICS, Inc – Reverse Amplifier with Step Attenuator

ARA2004
Reverse Amplifier with Step Attenuator
Data Sheet - Rev 2.1
FEATURES
• Low Cost Integrated Amplifier with Step
Attenuator
• Attenuation Range: 0-58 dB, adjustable in 1 dB
increments via a 3 wire serial control
• Meets DOCSIS distortion requirements at +60
dBmV output signal level
• Low distortion and low noise
• Frequency range: 5-100 MHz
• 5 Volt operation
• -40 to +85 ^oC 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
Clock
Data
Enable
S12 Package
28 Pin SSOP
with Heat Slug
performance 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.
Balun
ARA2004
Low Pass
Filter
Upstream
QPSK/16QAM
Modulator
5-42 MHz
Transmit Enable/Disable
Clock
Data
MAC
Diplexer
54-860 MHz
Double-
Conversion
Tuner
44 MHz
SAW
Filter
Clock
Data
QAM Receiver
with FEC
RAM ROM
Microcontroller
with Ethernet
MAC
10Base-T
Transceiver
RJ45
Connector
Figure 1: Cable Modem or Set Top Box Application Diagram
07/2005