
07-2001
ARA1400/ARA1400I
Reverse Amplifier with Step Attenuator
Data Sheet - Rev 2.0
FEATURES
Low cost integrated monolothic GaAs amplifier
with step attenuator
Attenuation Range: 0-56 dB, adjustable in
4dB increments via a 4 wire parallel control
Meets DOCSIS distortion requirements at
+60dBmV output signal level
Low distortion and low noise
Frequency range: 5-100MHz
5 Volt operation
-40 to +85 0C or 0 to +85 0C temperature range
options available
APPLICATIONS
MCNS/DOCSIS Compliant Cable Modems
CATV Interactive Set-Top Box
Telephony over Cable Systems
OpenCable Set-Top Box
Residential Gateway
The ARA1400 and the ARA1400I are GaAs ICs
designed to provide the reverse path amplification
and output level control functions in a CATV Set-Top
Box or Cable Modem. Each 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. These
devices are capable of meeting the MCNS/DOCSIS
requirements for harmonic performance at a
+60dBmV output level while requiring only a single
polarity +5V supply. On each device, both the input
and the output are single-ended and matched to 75
Ohms, and a precision attenuator provides up to 56
dB of attenuation in 4 dB increments. Both devices
are offered in a 28-pin SSOP package featuring a
heat slug on the bottom of the package. Two
temperature range options are available: the
ARA1400 for commercial applications, and the
ARA1400I for industrial applications.
PRODUCT DESCRIPTION
Figure 1. Cable Modem or Set Top Box Application Diagram
S12 Package
28 Pin SSOP with Heat Slug
Diplexer
ARA1400
or
ARA1400
,
SAW
Filter
Double-
Conversion
Tuner
MAC
Upstream
QPSK/16QAM
Modulator
QAM Receiver
with FEC
Balun
Transmit Enable/Disable
Attenuation Control
Microcontroller
with Ethernet
MAC
RAM
ROM
10Base-T
Transceiver
RJ45
Connector
Clock
Data
54-860 MHz
44 MHz
5-42 MHz
4
LPF