ARA2005 Datasheet, PDF (1/16 Pages) ANADIGICS, Inc – Reverse Amplifier with Step Attenuator

FEATURES
· Low cost integrated monolithic GaAs amplifier
with step attenuator
· Attenuation Range: 0-58 dB, adjustable in
4dB increments via a 4 wire parallel control
· Meets DOCSIS distortion requirements at a
+60dBmV output signal level
· Low distortion and low noise
· Frequency range: 5-100MHz
· 5 Volt operation
· -40 to +85 ⁰C temperature range
APPLICATIONS
· MCNS/DOCSIS Compliant Cable Modems
· CATV Interactive Set-Top Box
· Telephony over Cable Systems
· OpenCable Set-Top Box
· Residential Gateway
ARA2005
Reverse Amplifier with Step Attenuator
PRELIMINARY DATA SHEET - Rev 1.3
S8 Package
28 Pin SSOP
PRODUCT DESCRIPTION
The ARA2005 is a monolithic GaAs device designed
to provide the reverse path amplification and output
level control functions in a Cable TV Set Top Box or
Cable Modem. It incorporates a digitally controlled
precision step attenuator, which is preceded by an
ultra low noise amplifier stage and followed by an
ulta-linear output driver amplifier. The ARA2005 uses
a balanced circuit design that exceeds the MCNS/
DOCSIS requirement for harmonic performance at a
+60 dBmV output level while requiring only a single
+5V supply. Both the input and output of the device
are matched to 75 Ohms with an appropriate
transformer. The precision attenuator provides up to
58 dB of attenuation in 4 dB increments,
programmable via a four-bit digital control 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 1.2/50mS
surge tests. The ARA2005 is offered in a 28-pin SSOP
package.
4 Attenuation Control
Balun
ARA2005
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
Figure 1: Cable Modem or Set Top Box Application Diagram
08/2001
RJ45
Connector