Preliminary Information
OR51142
Demodulator
January 2003
The OR51142 is a sophisticated DSP-based demodulator IC for ATSC VSB and QAM DTV signals.
OR51142 Simplified Block Diagram
OR51142
Programmable Digital
Filters and other
DSP Blocks
DSP Processor
RF
Tuner
NCO
Firmware
RAM
FEC
Circuits
AGC
IIC Host Interface
General Purpose I/O Pins
SPI or ROM Interface
MPEG-2 Transport Stream
(Parallel or Serial Format)
10-bit
ADC
RF
AGC
IF
AGC
The OR51142 builds on Oren's powerful and efficient demodulator DSP technology, adding accelerated 8-VSB for ATSC demodulation.
The OR51142 uses adaptable filter blocks controlled by a central DSP processor. This proprietary implementation results in many
application benefits:
Superior Modulation Flexibility
VSB ATSC demodulation
64/256-QAM demodulation for OpenCable
TM
applications
(ITU-T j.83 annex B)
Ideal for iDTVs, set-tops, and PC products
Excellent VSB Performance
Superior VSB multi-path, adjacent channel rejection with
adjustable -15 to +45
s using a 576-tap full equalizer
Handles large carrier offset (+/-500khz) using the
embedded search algorithm
Fast channel acquisition and recover algorithms, with both
blind and trained equalization
Dynamically programmable matched filters compensate for
carrier frequency offset, and adjacent channel interference
Comprehensive FEC Integration
Reed-Solomon decoder
Soft Viterbi decoder
Autonomous Operation
Internal firmware execution eliminates supervision and
operation by the system host
Internal DSP controls all aspects of operation including
filter training and re-acquisition
Automatic adjustments are made for impairments like
NTSC interference
Low Power
Power dissipation is less than 1.0 Watt using 3.3V
peripheral, and 1.8V core supplies
Standard 128-pin QFP package
Advanced System Functions
Accepts 44MHz or low-IF from the tuner eliminating
external base-band demodulation
Separate RF and IF AGC outputs with adaptive tuner
gain delay and loop parameters
Fast channel re-lock through restoration of channel
parameters
Internal NCO clock source eliminates external VCXO
requirements
Via IIC, the OR51142 independently calculates and
reports FEC statistics, receiver status, and channel data
such as S/N ratio, equalizer taps, carrier offset, and
more.
Flexible Firmware Initialization Options
Three firmware loading options:
- IIC serial bus from host
- Auto-boot from SPI memory chip
- Auto-boot from ROM interface
Approximately 20kB firmware space
Oren Semiconductor, Inc.
2700 Augustine Drive, Suite 155, Santa Clara, CA 95054 tel: 408.330.0300 fax: 408.330.0305
www.oren.com
rev.
0.2
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