Demodulator

A Demodulator (short Demod) recovers (demodulates) the original information from the received and downconverted RF signal -- a tuner acquires the RF signal and converts it to an intermediate frequency (IF) which is then passed onto the demodulator for processing. The type of demodulator IC used for this task of information recovery is specific and dependent upon the nature of the signal transmission scheme involved.

In the case of analog TV, the IF inputted into the demodulator contains the composite signal that was originally modulated onto the RF carrier. After recovery, the demodulator outputs a CVSB signal, which will then need to be digitized through sampling techniques performed by a A/V decoder.

In the case of digital TV transmission schemes, the IF inputted into the demodulator contains a MPEG2 Transport Stream (TS) that was originally modulated onto the RF carrier. In the process of recovering that TS, digital demodulators will perform Forward Error Correction (Convolutional Viterbi- and Block-Reed-Solomon-Decoding). This whole process is sometimes referred to as RF-to-bits, for, unlike the case with analog IF demodulators, the recovered signal outputted from the digital demodulator is already a digital bit stream; specifically a TS. The TS will in turn be sent to a decoder in order to display (and, depending upon what format the underlying video content contained within the TS was encoded with, this could be a MPEG2 or MPEG4 decoder ... and either hardware or software based).

Demodulator Chipsets

Analogue IF Demodulators

A Sortable List of Analog IF Demodulators

Vendor	Model	Standards	Linux Support	Comments
Philips	TDA9887	NTSC	Yes	-
Xceiev	XC3028	NTSC, PAL	er, somewhat	firmware galore

... an so on ...

Digital Demodulators

A Sortable List of Digital Demodulators

Vendor	Model	Standard	Linux Support	Comments
ATI/AMD	Nxt2000	ATSC	?	Supports 8-VSB, QAM; firmware required
ATI/AMD	Nxt2002	ATSC	yes	Supports 8-VSB, QAM; firmware required
ATI/AMD	Nxt2004	ATSC	yes	Supports 8-VSB, QAM; firmware required
ATI/AMD	Theater 31x	ATSC	no	Supports 8-VSB, QAM
Philips	TDA10021	DVB-C	yes	Supports QAM
Philips	TDA10045	DVB-T	yes	Supports COFDM
Philips	TDA10046	DVB-T	yes	Supports COFDM
Philips	TDA8083	DVB-S	yes	supports QPSK
STMicroelectronics	STV0297	DVB-C	yes	supports QAM
STMicroelectronics	STV0299	DVB-S	yes	supports QPSK
STMicroelectronics	STB0899	DVB-S2	yes	supports 8PSK, QPSK
STMicroelectronics	STV0900/3	DVB-S2	?	supports QPSK
VLSI Technology	VES1893	DVB-S	yes	supports QPSK
VLSI Technology	VES1993	DVB-S	yes	supports QPSK
VLSI Technology	VES1820	DVB-C	yes	supports QAM
Zarlink Semiconductor	MT312	DVB-S/DSS	yes	supports QPSK
Zarlink Semiconductor	MT352	DVB-T	yes	supports QPSK
Zarlink Semiconductor	ZL10312	DVB-S/DSS	no	supports QPSK
Zarlink Semiconductor	ZL10313	DVB-S/DSS	no	supports QPSK

...and so on ...

Note: Info below needs to be added to table above

ATSC Demodulators

• LG DT3302
• LG DT3303
• Oren
• Oren
• Samsung s5h
• Zoran/Oren Cascade

....

DVB-T Demodulators

• Afatech AF9005
• Afatech AF9015

...

DVB-S2 Demodulators

• Commsonic CMS0014
• Conexant CX24116
• Eccincorp ECC3100 (SkyPHY)

...

Some Examples for Digital Demods are

Model	Type and Vendor
NXT6000	DVB-T/COFDM Demod produced by ATI
AT76C651	DVB-C/QAM Demod produced by Atmel Corporation
CX22700	DVB-T/COFDM Demod produced by Conexant Systems, Inc.
CX24110	DVB-S/QPSK Demod produced by Conexant Systems, Inc.
DIB3000M	DVB-T/COFDM Demod produced by DiBcom
L64781	DVB-T/COFDM Demod produced by LSI Logic Corporation
L64782	DVB-T/COFDM Demod produced by LSI Logic Corporation
MT8872/SP8872	DVB-T/COFDM Demod produced by Microtune/SPaSE
SP8870	DVB-T/COFDM Demod produced by SPaSE

Also see

• List of Chipset Vendors