BCM3125 Datasheet, PDF (1/2 Pages) Broadcom Corporation. – UNIVERSAL TRANSMISSION SOLUTION

BCM312 5
PRODUCT
®
Brief
BCM312 5 QAMLink^® UNIVERSAL TRANSMISSION SOLUTION
BCM3125 FEATURES
• ^{Integrated QAMLink® in-band receiver}
• 10-bit A/D converter with input AGC amplifier
• Variable symbol rate 256-QAM receiver
• Digital demodulator, Nyquist filters, tracking loops,
and 32-tap adaptive decision feedback equalizer
• ITU-T J.83 Annex A/B/C compatible FEC decoder
• ^{Integrated QPSK out-of-band receiver}
• Baseband interface to dual 6-bit A/D converters or IF
interface to signal A/D converter
• Variable symbol rate QPSK receiver
• Digital demodulator, Nyquist filters, tracking loops,
and 4-tap adaptive decision feedback equalizer
• DigiCipher^®II/DVB/DAVIC FEC decoder
• MPEG transport output interface/DAVIC MAC
output interface
• ^{Integrated upstream transmitter}
• Programmable Starvue
II/DOCSIS™/EuroDOCSIS™/DVB/ DAVIC FEC
encoder
• Pre-equalization filter
• Up to 6 MBaud variable rate QPSK/16-QAM modulator
• 10-bit D/A converter with output power control
interfaces
• ^{Control unit}
• BSC/SPI compatible interface for configuration and
device control
• RF tuner control
• ^{160-pin PQFP package}
SUMMARY OF BENEFITS
• Universal set-top and cable modem front-end
supports the ITU-T J.83 Annex A/B/C standards, as
well as OpenCable™, DOCSIS/EuroDOCSIS, and
DVB/DAVIC
• Connects directly to Broadcom digital TV ICs
supporting physical layer requirements including
out-of-band
• Represents a complete solution for dual
downstream channels (in-band and out-of-band) and
the upstream channel
• Integrated analog front end for the dual downstream
and upstream blocks reduces board complexity and
system costs
• Serial control interface results in reduced overall pin
count
• Out-of-band QPSK receiver provides flexibility for
IF or baseband inputs
• Single, low-cost crystal solution eliminates costly
VCXOs
• Includes direct interface to the OpenCable point-of-
deployment (POD) module
• Single device supports both 6-MHz and 8-MHz
channels
• Allows direct connection to Broadcom ICs to support
additional data and video channels for
DOCSIS/EuroDOCSIS/DAVIC systems and PVR set-
top boxes
Set-Top Box Block Diagram
Tuner
In-Band Channel
Out-of-Band Channel
Upstream Channel
BCM3125
QAMLink^®
Universal
Transmission
Solution
BCM7020/BCM7030
High Definition Video /
Graphics Subsystem
Audio
Video
CPU
I/O
Memory