ARA2001S23
CATV Reverse Amplifier with Step Attenuator
Advanced Product Information -
Rev. 2
FEATURES
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Low cost integrated monolithic GaAs
amplifier with step attenuator.
Attenuation Range: 0 58 dB, variable in
1 dB steps via 8 bit serial input.
Meets DOCSIS distortion requirements at
+60 dBmV
Low distortion & Low noise figure
Frequency range: 5 100 MHz
5 Volt operation
APPLICATIONS
MCNS/DOCSIS Compliant Cable Modems
CATV Interactive Set-Top Box
Telephony over Cable Systems
Open Cable Set-Top Box
S23
28 PIN SSOP PACKAGE
Description
The ARA2001S23 is a GaAs IC 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 part is a balanced design that meets or exceeds the MCNS/DOCSIS requirement for
harmonic performance @ +60dBmV output levels while only requiring a single polarity +5V supply. Both the
input and output are matched to 75 ohms. The precision attenuator provides up to 58 dB of attenuation in 1
dB increments. The ARA2001S23 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.
Tx Enable/Disable
Gain Control
DAT
CLK
"Shutdown"
EN
CMOS IC
Upstream
QPSK/
16-QAM
Modulator
PA
~
PA
ARA
2001
Reverse Amp
Low Pass
Filter
Balun
ATTN
1/2/4/8/16/32 dB
PA
Low Pass
Filter
~
PA
Clock
Data
Microcontroller
w/Enet MAC
RAM
ROM
MAC
"Shutdown"
Clock
45 MHz IF
Data
Diplexer
Filter
54-860 MHz
Double
Conversion
Tuner
SAW
QAM
Receiver
w/FEC
10Base-T
Tranceiver
RJ45
Connector
Coax Input
Figure 1: Cable Modem or Interactive Set-Top Box Block Diagram
ANADIGICS [ ANADIGICS, INC ]
