Moteur de recherche de fiches techniques de composants électroniques
  French  ▼
ALLDATASHEET.FR

X  

TDA8046H Fiches technique(PDF) 9 Page - NXP Semiconductors

No de pièce TDA8046H
Description  Multi-mode QAM demodulator
Download  48 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  PHILIPS [NXP Semiconductors]
Site Internet  http://www.nxp.com
Logo PHILIPS - NXP Semiconductors

TDA8046H Fiches technique(HTML) 9 Page - NXP Semiconductors

Back Button TDA8046H Datasheet HTML 5Page - NXP Semiconductors TDA8046H Datasheet HTML 6Page - NXP Semiconductors TDA8046H Datasheet HTML 7Page - NXP Semiconductors TDA8046H Datasheet HTML 8Page - NXP Semiconductors TDA8046H Datasheet HTML 9Page - NXP Semiconductors TDA8046H Datasheet HTML 10Page - NXP Semiconductors TDA8046H Datasheet HTML 11Page - NXP Semiconductors TDA8046H Datasheet HTML 12Page - NXP Semiconductors TDA8046H Datasheet HTML 13Page - NXP Semiconductors Next Button
Zoom Inzoom in Zoom Outzoom out
 9 / 48 page
background image
1996 Nov 19
9
Philips Semiconductors
Product specification
Multi-mode QAM demodulator
TDA8046
7.1
Functional description of the individual blocks
The functional block diagram of the multi-mode QAM
demodulator is illustrated in Fig.1. This section describes
the individual blocks in the demodulator. After adaptation
for the used input format (2’s complement or binary), the
input signal is demodulated in the I and Q baseband
signals which are applied to the inputs of the half-Nyquist
filter (equals square root raised cosine). To avoid
overloading of the ADC, an AGC detector is placed after
the adaptation for the input format. The control value for
the clock recovery is generated after half Nyquist filtering.
The echoes created in the cable network are reduced
significantly in the equalizer.
The equalizer produces a ‘clean’ constellation diagram
from which the information for the carrier recovery is
derived. This constellation is also applied to the output
formatter which demaps the transmitted symbols in
corresponding bits. The carrier recovery and lock
detection functions are based on the equalizer output.
The output of the equalizer is applied to an output
formatter, which translates the symbol bits to a FEC input
format. The digital outputs of the clock recovery, AGC, and
carrier recovery section are converted into currents which
are integrated by the loop filters.
To make these loop filters active, operational amplifiers
are integrated on the chip.
The TDA8046 can handle five different digital modulation
schemes; 4, 16, 32, 64 and 256-QAM. These schemes
are selectable via the I2C-bus interface.
7.1.1
QUADRATURE DEMODULATOR AND HALF NYQUIST
FILTER
Quadrature demodulation is accomplished after selection
of the appropriate input format via the I2C-bus.
The in-phase and quadrature components are both
applied to a half Nyquist filter. In default mode, this filter
gives a 20% roll-off half Nyquist shaping. The basic
schematic of the quadrature demodulator followed by the
half Nyquist filter is shown in Fig.4. The signs of the
multiplication factors in the Q-branch can be inverted
(I2C-bus bit INVD).
When using an 8-bit ADC the LSB of the 9-bit input word
should be connected to the positive supply (VDDD).
This ensures a symmetrical 2’s complement
representation which can be multiplied by
−1 in a correct
(2’s complement) way. The overall transfer function of the
square root raised cosine filters is shown in Figs 5 and 6.
For characteristics see Chapter 10.
Fig.4 Schematic diagram of the quadrature demodulator and half Nyquist filter.
handbook, full pagewidth
HALF NYQUIST
FILTER
HALF NYQUIST
FILTER
+1, 0, −1, 0
0,
−1, 0, +1
9
9
DIN8
to
DIN0
BINARY OR
TWO's
COMPLEMENT
I
I2C-BUS
I2C-BUS
Q
MGG168
9
I2C-BUS
I2C-BUS


Numéro de pièce similaire - TDA8046H

FabricantNo de pièceFiches techniqueDescription
logo
NXP Semiconductors
TDA8040T PHILIPS-TDA8040T Datasheet
88Kb / 16P
   Quadrature demodulator
1996 Oct 08
TDA8041H PHILIPS-TDA8041H Datasheet
95Kb / 16P
   Quadrature demodulator controller
November 1994
TDA8042 PHILIPS-TDA8042 Datasheet
108Kb / 16P
   Quadrature demodulator
1997 Apr 11
TDA8042M PHILIPS-TDA8042M Datasheet
108Kb / 16P
   Quadrature demodulator
1997 Apr 11
TDA8043 PHILIPS-TDA8043 Datasheet
95Kb / 16P
   Satellite Demodulator and Decoder SDD
1998 Feb 13
More results

Description similaire - TDA8046H

FabricantNo de pièceFiches techniqueDescription
logo
List of Unclassifed Man...
CS3810 ETC1-CS3810 Datasheet
265Kb / 12P
   32 QAM Demodulator
logo
Sony Corporation
CXD1958Q SONY-CXD1958Q Datasheet
332Kb / 48P
   MMDS TCM/QAM Demodulator FEC ADC
logo
STMicroelectronics
STV0297E STMICROELECTRONICS-STV0297E Datasheet
81Kb / 5P
   QAM demodulator IC with A/D converter
STI7197 STMICROELECTRONICS-STI7197 Datasheet
97Kb / 4P
   Advanced STB decoder with integrated QAM demodulator
logo
ATMEL Corporation
AT76C651B ATMEL-AT76C651B Datasheet
82Kb / 7P
   Digital Reception/ Transmission IC Integrated DVB compliant QAM Demodulator
logo
CML Microcircuits
CMX991 CMLMICRO-CMX991 Datasheet
2Mb / 56P
   Two-mode demodulator
logo
STMicroelectronics
QAMI5107 STMICROELECTRONICS-QAMI5107 Datasheet
93Kb / 6P
   Low-cost QAM demodulator and MPEG2 decoder SOC for set-top boxes
STI5197 STMICROELECTRONICS-STI5197 Datasheet
84Kb / 4P
   Cost-effective QAM demodulator and MPEG2 decoder for SD set-top box applications
logo
Texas Instruments
TVP9900 TI-TVP9900 Datasheet
906Kb / 65P
[Old version datasheet]   VSB/QAM Receiver
logo
Fairchild Semiconductor
RC2798 FAIRCHILD-RC2798 Datasheet
76Kb / 12P
   Integrated QAM IF Downconverter
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48


Fiches technique Télécharger

Go To PDF Page


Lien URL




Politique de confidentialité
ALLDATASHEET.FR
ALLDATASHEET vous a-t-il été utile ?  [ DONATE ] 

À propos de Alldatasheet   |   Publicité   |   Contactez-nous   |   Politique de confidentialité   |   Echange de liens   |   Fabricants
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com