Philips Semiconductors
Preliminary specification
Digital TV sound demodulator/decoder
1
FEATURES
TDA9874H
•
SIF input switch e.g. to select between terrestrial TV SIF
and SAT SIF sources
•
SIF AGC with 21 dB control range
•
SIF 8-bit Analog-to-Digital Converter (ADC)
•
DQPSK demodulation for different standards,
simultaneously with 1-channel FM demodulation
•
NICAM decoding (B/G, I and L standard)
•
Two-carrier multi-standard FM demodulation
(B/G, D/K and M standard)
•
Decoding for three analog multi-channel systems
(A2, A2+ and A2*) and satellite sound
•
Adaptive de-emphasis for satellite
•
Programmable identification (B/G, D/K and M standard)
and different identification times
•
Optional AM demodulation for system L, simultaneously
with NICAM
•
Monitor selection for FM/AM demodulator outputs and
FM and NICAM signals
•
Digital crossbar switch
•
I
2
S serial audio output with matrix, level adjust and mute
•
Dual audio Digital-to-Analog Converter (DAC) from
digital crossbar switch to analog crossbar switch,
bandwidth 15 kHz
•
Analog crossbar switch with inputs for mono and stereo
•
Output selection of mono, stereo, dual, dual A or dual B
•
20 kHz bandwidth for analog path
•
Standby mode.
2
GENERAL DESCRIPTION
2.1
Supported standards
The multi-standard/multi-stereo capability of the
TDA9874H is mainly of interest in Europe, but also in
Hong Kong/PR China and South East Asia. This includes
B/G, D/K, I, M and L standard. In other application areas
there exist subsets of those standard combinations or only
single standards are transmitted.
Standard M is transmitted in Europe by the American
Forces Network with European channel spacing
(7 MHz VHF, 8 MHz UHF) and monaural sound.
The AM sound of L/L’ standard is normally demodulated in
the 1st sound IF. The resulting AF signal has to be entered
into the mono audio input of the TDA9874H. A second
possibility is to use the internal AM demodulator stage,
giving limited performance.
Korea has a stereo sound system similar to Europe and is
supported by the TDA9874H. Differences include
deviation, modulation contents and identification. It is
based on M standard.
An overview of the supported standards and sound
systems and their key parameters is given in Table 1.
The analog multi-channel systems are sometimes also
named 2CS (2 carrier systems).
The TDA9874H is a single-chip Digital TV Sound
Demodulator/Decoder (DTVSD1) for analog and digital
multi-channel sound systems in TV/VCR sets and satellite
receivers.
1998 Apr 27
3
Philips Semiconductors
Preliminary specification
Digital TV sound demodulator/decoder
2.1.3
S
ATELLITE SYSTEMS
TDA9874H
An important specification for satellite TV reception is the Astra specification. The TDA9874H is suited for the reception
of Astra and other satellite signals, with sound carrier frequencies from 4 to 9.2 MHz.
Table 4
FM satellite sound
CARRIER
FREQUENCY
(MHz)
6.50
(1)
7.02/7.20
7.38/7.56
7.74/7.92
8.10/8.28
MODULATION
INDEX
0.26
0.15
0.15
0.15
0.15
MAXIMUM
FM DEVIATION
(kHz)
85
50
50
50
50
MODULATION
mono
m/st/d
(2)
m/st/d
(2)
m/st/d
(2)
m/st/d
(2)
BANDWIDTH/
DE-EMPHASIS
(kHz/µs)
15/50
(1)
15/adaptive
(3)
15/adaptive
(3)
15/adaptive
(3)
15/adaptive
(3)
CARRIER TYPE
Main
Sub
Sub
Sub
Sub
Notes
1. For other satellite systems, frequencies of e.g. 5.80 MHz, 6.60 MHz or 6.65 MHz can also be received.
A de-emphasis of 60
µs
or in accordance with J17 is available.
2. m/st/d = mono or stereo or dual language sound.
3. Adaptive de-emphasis = compatible to transmitter specification.
3
ORDERING INFORMATION
TYPE
NUMBER
PACKAGE
NAME
DESCRIPTION
VERSION
SOT205-1
TDA9874H QFP44 plastic quad flat package; 44 leads (lead length 2.35 mm); body 14
×
14
×
2.2 mm
1998 Apr 27
5
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