TDA9874AHB NXP Semiconductors, TDA9874AHB Datasheet - Page 27
TDA9874AHB
Manufacturer Part Number
TDA9874AHB
Description
Audio Amplifiers DIGITAL STEREO DECODER VCR
Manufacturer
NXP Semiconductors
Datasheet
1.TDA9874AHB.pdf
(68 pages)
Specifications of TDA9874AHB
Product
General Purpose Audio Amplifiers
Maximum Operating Temperature
+ 70 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 20 C
Package / Case
PQFP-44
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
TDA9874AH/V2,557
Philips Semiconductors
Table 28 Filter bandwidth for channel 1 and channel 2; note 1
Note
1. It is recommended to switch the FM sound mode identification off whenever the received program is not a terrestrial
7.3.8
This register should not be used when applying ESP. This register is used to select the proper de-emphasis
characteristics as appropriate for the standard of the received carrier. Bits 3 to 0 apply to sound carrier 1, bits 7 to 4 apply
to sound carrier 2. In the event of A2 reception, both groups must be set to the same characteristics.
The default setting after Power-on reset is 0000 0000.
Table 29 FM de-emphasis register (subaddress 10)
Table 30 Description of the FM de-emphasis register bits
2000 Aug 04
Digital TV sound demodulator/decoder
FILTBW1
ADEEM2
2-carrier sound. Switching the identification off will reset the associated hardware to a defined state.
BIT
0
0
1
1
7
7
6
5
4
3
2
1
0
FM
DE
-
EMPHASIS REGISTER
FMDSC23
FMDSC23
FMDSC22
FMDSC21
FMDSC13
FMDSC12
FMDSC11
FILTBW0
SYMBOL
ADEEM1
ADEEM2
0
1
0
1
6
Adaptive de-emphasis on/off sound carrier 2: if bit ADEEM2 = 1 it activates the adaptive
de-emphasis function (for Wegener-Panda 1 encoded programs), which is required for
certain satellite FM channels. The standard FM de-emphasis must then be set to 75 s.
If bit ADEEM2 = 0 the adaptive de-emphasis is off.
FM de-emphasis: the state of these bits determines the FM de-emphasis for sound
carrier 2; see Table 31.
Adaptive de-emphasis on/off sound carrier 1: if bit ADEEM1 = 1 it activates the adaptive
de-emphasis function (for Wegener-Panda 1 encoded programs), which is required for
certain satellite FM channels. The standard FM de-emphasis must then be set to 75 s.
If bit ADEEM1 = 0 the adaptive de-emphasis is off.
FM de-emphasis: the state of these bits determines the FM de-emphasis for sound
carrier 1; see Table 31.
CHANNEL 1
FMDSC22
extra wide
medium
narrow
FILTER BANDWIDTH
wide
5
FMDSC21
CHANNEL 2
medium
narrow
narrow
4
wide
27
ADEEM1
recommended for nominal terrestrial broadcast
conditions and SAT with 2 carriers
Recommended for highly overmodulated single
FM carriers. Only channel 1 is available for
FM demodulation in this mode. NICAM can still be
processed on channel 2.
recommended for moderately overmodulated
broadcast conditions
recommended for strongly overmodulated broadcast
conditions
3
DESCRIPTION
FMDSC13
2
FILTER MODES
FMDSC12
1
Product specification
TDA9874A
FMDSC11
0