E-TDA7402 [STMICROELECTRONICS]
SPECIALTY CONSUMER CIRCUIT, PQFP44, 10 X 10 MM, 1.40 MM HEIGHT, ROHS COMPLIANT, TQFP-44;
| 型号： | E-TDA7402 |
| 厂家： | 
ST |
| 描述： | SPECIALTY CONSUMER CIRCUIT, PQFP44, 10 X 10 MM, 1.40 MM HEIGHT, ROHS COMPLIANT, TQFP-44 商用集成电路 |
| 文件： | 总69页 (文件大小：826K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
TDA7402
Car radio signal processor
Features
■ 3 stereo inputs
■ 3 mono inputs
■ Dynamic-compression-stage for cd
■ Soft Step volume
■ Bass, treble and loudness control
■ Voice-band filter
LQFP44
■ Direct mute and Soft Mute
■ Internal beep
■ Four independent speaker-outputs
■ Stereo subwoofer output
■ Independent second source-selector
■ Full mixing capability
■ Pause detector
Digital control
2
■ I C us interface
Description
The device includes a high performance
audioprocessor and a stereo decoder-noise
blanker combination, with the whole low
frequency signal processing necessary for state
of the art, as well as future car radios. The digital
control allows a programming in a wide range of
all the filter characteristics. The stereo decoder
part also offers several possibilities of
Stereo decoder
■ RDS mute
■ No external adjustments
■ AM/FM noiseblaer with several trigger
controls
programming, especially for the adaptation to
different IF devices.
■ Programmable multipath detector
■ Quality detector output
Tble 1.
Device summary
Order code
Package
LQFP44 (10x 10x 1.4mm)
Packing
TDA7402
Tray
September 2008
Rev 6
1/69
www.st.com
1
Contents
TDA7402
Contents
1
2
3
Pin connections and block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Audioprocessor part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1
3.2
Audioprocessor part features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Input stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
Full differential stereo input 1 (FD1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Full differential stereo input 2 (FD2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Mono differential input 1 (MD1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Mono differential input 2 (MD2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Single ended stereo input (SE1), single ended mono input (AM)
and FM-MPX input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3
3.4
AutoZero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3.1
3.3.2
AutoZero for stereo decoder selection . . . . . . . . . . . . . . . . . . . . . . . . . . 17
AutoZero remain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Pause detector / MUX-output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.4.1
3.4.2
3.4.3
.4.4
3.4.5
Loudness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Peak frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Loudness order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Flat mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.5
3.6
3.7
Soft Mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Soft Step volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Bass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.7.1
3.7.2
3.7.3
3.7.4
Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Quality factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
DC mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.8
3.9
Treble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.8.1
3.8.2
Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Subwoofer application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.10 Voice band application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2/69
TDA7402
Contents
3.11 Compander . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.11.1 Anti-clipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.11.2 Characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2
3.11.3 I C bus timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.12 AC coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.13 Output selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.14 Subwoofer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.15 Speaker attenuator and mixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.16 Audioprocessor testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4
Stereo decoder part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.1
4.2
4.3
Stereo decoder part features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Stereo decoder electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 31
Notes about the characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.3.1
4.3.2
4.3.3
4.3.4
Intermodulation suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Traffic radio (V.F.) suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
SCA (subsidiary commuations authorization) . . . . . . . . . . . . . . . . . . 33
ACI (adjacent channinterference) . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.4
4.5
Noise blanker part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.4.1
Noise blanker part features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Multipath detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.5.1
Multipath detector features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5
Functional description of stereo decoder . . . . . . . . . . . . . . . . . . . . . . . 38
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
Stereo decoder mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
InGain + infilter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Demodulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
De-emphasis and highcut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
PLL and pilot tone detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Fieldstrength control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
EVEL input and gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Stereo blend control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Highcut control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
6
Functional description of the noise blanker . . . . . . . . . . . . . . . . . . . . . 43
3/69
Contents
TDA7402
6.1
6.2
6.3
Trigger path FM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Noise controlled threshold adjustment (NCT) . . . . . . . . . . . . . . . . . . . . . 43
Additional threshold control mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.3.1
6.3.2
6.3.3
6.3.4
Automatic threshold control by the stereo blend voltage . . . . . . . . . . . . 44
Over deviation detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Multipath level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
AM mode of the noiseblanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
7
8
Functional description of the multipath detector . . . . . . . . . . . . . . . . . 45
7.1
7.2
7.3
Quality detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Testmode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Dual MPX usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.3.1
7.3.2
Feature description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2
I C bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
8.1
8.2
8.3
8.4
8.5
Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Auto increment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Transmitted data (send mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Subaddress (receive mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Data byte specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
9
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
10
11
4/69
TDA7402
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Device summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Attack times vs. soft-step times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Stereo decoder electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Noise blanker electrical characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Multipath detector electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Transmitted data (send mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Reset condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Subaddress (receive mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Main selector (0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Main loudness (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Volume (2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Treble filter (3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Bass filter (4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Mixing programming (5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Soft mute (6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Voiceband (7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Second source selector (8). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Second loudness (9). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Subwoofer configuration / Bass (10). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Compander (11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Configuration audioprocessor I (12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Configuration audioprocessor II (13) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Speaker, subwoofer and mixer level-control (14-20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Testing Audiopressor (21). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Stereo decod(22) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Noise anker I (23) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Noiseblanker II (24) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
AM / FM noiseblanker (25) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
High cut (26) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Fieldstrength control (27) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Multipath detector (28) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Stereo decoder adjustment (29) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Stereo decoder configuration (30) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Testing stereo decoder (31) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
Table 16.
Table 17.
Table 18.
Table 19.
Table 20.
Table 21.
Table 22.
Table 23.
Table 24.
Table 25.
Table 26.
Table 27.
Table 28.
Table 29.
Table 30.
Table 31.
Table 32.
Table 33.
Table .
Tble 35.
Table 36.
Table 37.
Table 38.
Table 39.
5/69
List of figures
TDA7402
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Pin connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Input-stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Loudness attenuation @ fP = 400Hz.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Loudness center frequencies @ Attn. = 15dB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1 and 2 order loudness @ Attn. = 15dB, fP=400Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Soft Mute timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Soft Step timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Bass control @ fC = 80Hz, Q = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
st
nd
Figure 10. Bass center frequencies @ gain = 14dB, Q = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 11. Bass quality factors @ Gain = 14dB, fC = 80Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 12. Bass normal and DC Mode @ Gain = 14dB, fC = 80Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 13. Treble control @ fC = 17.5kHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 14. Treble center frequencies @ gain = 14dB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 15. Subwoofer application with LPF 80/120/160Hz and HPF 90/135/180z . . . . . . . . . . . . . . 24
Figure 16. Voiceband application with HPF 300/450/600/750Hz and LPF 3k/6kHz . . . . . . . . . . . . . . 24
Figure 17. Compander block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 18. Compander characteristic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 19. Output selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 20. Application 1 using internal highpass and mono lw pass filter . . . . . . . . . . . . . . . . . . . . . 28
Figure 21. Application 2 using internal highpass and eternal stereo low pass filter. . . . . . . . . . . . . . 29
Figure 22. Application 3 using pure external filter(e.g. DSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 23. Output selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 24. Vn timing diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 25. Trigger threshold vs. VPEAK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 26. Deviation controlled trigger adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 27. Field strength controlled trigger adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 28. Block diagram otereo decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Figure 29. Signals durinstereo decoder's Soft Mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figure 30. Signal ontrol via Soft Mute pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figure 31. Internal stereo blend characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 32. Relation between internal and external LEVEL voltages for setup of stereo blend . . . . . . 41
Figure 33. Highcut characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 4. Block diagram of the noise blanker. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Fgure 35. Block diagram of the multipath detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Figure 36. Dual MPX input diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Figure 37. Application diagram (standard configuration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Figure 38. Application diagram (Dual MPX mode). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Figure 39. LQFP44 (10x10) mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . 67
6/69
TDA7402
Pin connections and block diagram
1
Pin connections and block diagram
Figure 1.
Pin connections (top view)
44 43 42 41 40 39 38 37 36 35 34
1
2
3
4
5
6
7
8
9
SE1L
SE1R
33
32
31
30
29
28
27
26
25
2
ACINLR
ACINRF
ACINRR
OUTLF
FD1L+/SE3L
FD1L-/SE2L
FD1R+/SE3R
FD1R-/SE2R
FD2L+
OUTLR
OUTRF
OUTRR
OUTSWL
OUTWR
OUTSL
OUTSSR
FD2L-
FD2R+
FD2R-
10
11
AM
12 13 14 15 16 17 18 19 20 222
D00AU1131
7/69
Pin connections and block diagram
Figure 2. Block diagram
TDA7402
1U30
0DA
C A I N L F
C A I N L R
C A I N R F
C A I N R R
S W I N L
S W I N R
C A O U T R
C A O U T L
8/69
TDA7402
Electrical specifications
2
Electrical specifications
V = 9V; T
= 25°C; R = 10kΩ; all gains = 0dB; f = 1kHz; unless otherwise specified.
S
amb
L
Table 2.
Symbol
Electrical characteristics
Parameter
Test condition
Min.
Typ.
Max.
Unit
Input selector
Rin
VCL
SIN
Input resistance
Clipping level
Input separation
all single ended Inputs
70
2.2
80
-1
100
2.6
100
0
130
kΩ
VRMS
dB
GIN MIN Min. input gain
GIN MAX Max. input gain
GSTEP Step resolution
+1
17
1.5
5
dB
13
0.5
5
15
1
dB
dB
Adjacent gain steps
1
mV
mV
mV
VDC
DC steps
G
MIN to GMAX
-10
6
10
Voffset Remaining offset with autozero
0.5
Differential stereo inputs
Input resistance
Rin
Differentia
70
100
130
kΩ
(see Figure 3)
-1
-5
0
-6
1
7
dB
dB
dB
dB
dB
µV
GCD
Gain
only at true differential input
-11
46
46
-12
70
60
9
-13
V
CM = 1VRMS @ 1kHz
CM = 1VRMS @ 10kHz
CMRR Common mde rejection ratio
V
eNO
Differential mono inputs
Rin Input impedance
Outpu-noise @ speaker outputs 20Hz - 20kHz, flat; all stages 0dB
15
72
Differential
CM = 1VRMS @ 1kHz
40
40
40
56
70
60
kΩ
dB
dB
V
CMRR Common mode rejection ratio
VCM = 1VRMS @ 10kHz
Beep control
VRMS Beep level
Mix-gain = 6dB
fBeep1
250
570
740
1.48
2.28
350
600
780
1.56
2.4
500
630
820
1.64
2.52
mV
Hz
fBeep2
Hz
fBeep
Beep frequency
fBeep1
kHz
kHz
fBeep1
9/69
Electrical specifications
TDA7402
Unit
Table 2.
Symbol
Electrical characteristics (continued)
Parameter Test condition
Min.
Typ.
Max.
Mixing control
MLEVEL Mixing ratio
GMAX Max. gain
Main / mix source
-6/-6
15
dB
dB
dB
dB
13
-83
0.5
17
-75
1.5
AMAX Max. attenuation
ASTEP Attenuation step
-79
1
Multiplexer output (1)
ROUT
RL
Output impedance
225
4
300
W
kΩ
nF
V
Output load resistance
Output load capacitance
DC voltage level
2
CL
10
VDC
4.3
4.7
Loudness control
ASTEP Step resolution
AMAX Max. attenuation
0.5
-21
1
1.5
-17
dB
dB
Hz
Hz
Hz
Hz
-19
200
400
600
800
fP1
fP2
fP3
fP4
180
360
540
720
220
440
660
880
fPeak
Peak frequency
Volume control
GMAX Max. gain
30
-83
0
32
-79.5
0.5
0
34
dB
dB
dB
dB
dB
dB
mV
mV
AMAX Max. attenuation
ASTEP Step resolion
-75
1
G = -20 to +20dB
G = -80 to -20dB
-0.75
-4
+0.75
EA
ET
Attenuation set error
Tracking error
DC steps
0
3
2
3
5
Adjacent attenuation steps
From 0dB to GMIN
0.1
0.5
VDC
Soft mute
A
Mute attenuation
Delay time
80
100
0.48
0.96
123
324
dB
ms
ms
ms
ms
V
MUTE
T1
T2
T3
T4
1
2
TD
70
170
600
1
200
VTH low Low threshold for SM Pin(2)
VTH high High threshold for SM Pin
2.5
V
10/69
TDA7402
Electrical specifications
Table 2.
Symbol
Electrical characteristics (continued)
Parameter
Test condition
Min.
Typ.
Max.
Unit
RPU
VPU
Internal pull-up resistor
Internal pull-up voltage
32
45
58
kΩ
3.3
V
Bass control
CRANGE Control range
ASTEP Step resolution
+14
0.5
54
+15
1
+16
1.5
66
dB
dB
Hz
Hz
Hz
Hz
Hz
Hz
Hz
Hz
fC1
60
fC2
63
70
77
fC3
72
80
88
fC4
81
90
99
fC
Center frequency
fC5
90
100
130
150
200
1
110
143
165
220
1.1
1.4
1.7
2.2
+1
fC6
117
35
180
0.9
1.1
1.3
1.8
-1
fC7
fC8
Q1
Q2
1.25
1.5
2
QBASS Quality factor
Q3
Q4
DC = off
DC = on
0
dB
dB
DCGAIN Bass-DC-gain
4
4.4
6
Treble control
CRANGE Control range
ASTEP Step resolution
+14
0.5
8
+15
1
+16
1.5
12
dB
dB
fC1
fC2
fC3
fC4
10
kHz
kHz
kHz
kHz
10
12
14
12.5
15
15
fC
Center frequency
18
17.5
21
Pause detector(3)
Window 1
Window 2
Window 3
40
80
mV
mV
mV
μA
V
VTH
Zero crossing threshold
160
25
IDELAY Pull-up current
15
35
VTHP
Pause threshold
3.0
11/69
Electrical specifications
TDA7402
Unit
Table 2.
Symbol
Electrical characteristics (continued)
Parameter
Test condition
Min.
Typ.
Max.
Speaker attenuator
Rin
Input impedance
35
14
50
15
-79
1
65
16
kΩ
dB
dB
dB
dB
dB
mV
GMAX Max. gain
AMAX Max. attenuation
ASTEP Step resolution
-83
0.5
80
-75
1.5
AMUTE Output mute attenuation
90
EE
Attenuation set error
DC steps
2
5
VDC
Adjacent attenuation steps
d = 0.3%
0.1
26
Audio outputs
VCLIP Clipping level
2.2
2
VRMS
kΩ
nF
RL
CL
Output load resistance
Output load capacitance
Output impedance
DC voltage level
10
100
4.7
ROUT
VDC
30
W
4.3
4.5
V
Voice bandpass
fHP1
fHP2
fHP3
fHP4
fHP5
fHP6
fHP7
fHP8
fLP1
fLP2
81
90
135
180
215
300
450
600
750
3
99
Hz
Hz
122
162
194
270
405
540
675
2.7
148
198
236
330
495
660
825
3.3
Hz
Hz
fHP
Highpass corner freqency
Hz
Hz
Hz
Hz
kHz
kHz
fLP
Lowpass corner frequency
5.4
6
6.6
Subwoofer attenuator
Rin Input impedance
35
14
50
15
-79
1
65
16
kΩ
dB
dB
dB
dB
dB
mV
GMAX Max. gain
AATTN Max. attenuation
ASTEP Step resolution
AMUTE Output mute attenuation
-83
0.5
80
-75
1.5
90
EE
Attenuation set error
DC steps
2
5
VDC
Adjacent attenuation steps
1
12/69
TDA7402
Electrical specifications
Table 2.
Symbol
Electrical characteristics (continued)
Parameter Test condition
Min.
Typ.
Max.
Unit
Subwoofer lowpass
fLP1
fLP2
fLP3
72
80
88
Hz
Hz
Hz
fLP
Lowpass corner frequency
108
144
120
160
132
176
Differential outputs(4)
1VRMS; AC coupled; THD=1%
2VRMS; AC coupled; THD=1%
1VRMS; AC coupled; THD=1%
2VRMS; AC coupled; THD=1%
CLmax at each output to ground
CLmax between output terminals
Output muted
1
2
2
4
kΩ
kΩ
kΩ
kΩ
nF
nF
mV
W
RL
load resistance at each output
RDL
load resistance differential
CLMAX Capacitive load at each output
CDLMAX Capacitive load differential
VOffset DC offset at pins
10
5
-10
4.3
10
100
4.7
15
ROUT
VDC
eNO
Output impedance
DC voltage level
Output noise
30
4.5
6
V
Output muted
µV
Compander
Vi < -46dB
19
29
dB
dB
GMAX max. compander gain
Vi < -46dB, Anti-clip = on
tAtt1
6
ms
tAtt2
12
ms
tAtt
Attack time
tAtt3
24
ms
tAtt4
49
ms
tRel1
390
780
1.17
1.56
0.5
1.0
2.0
0.5
ms
tRel2
ms
tRel
Release time
tRel3
s
tRel4
s
VREF1
VRMS
VRMS
VRMS
Compander reference input-level
(equals 0dB)
VREF
VREF2
VREF3
CF
Compression factor
Output signal / input signal
13/69
Electrical specifications
TDA7402
Unit
Table 2.
Symbol
Electrical characteristics (continued)
Parameter Test condition
Min.
Typ.
Max.
General
BW = 20Hz - 20kHz
output muted
eNO
Output noise
3
15
20
µV
µV
all gains = 0dB single ended
inputs
10
all gains = 0dB
106
dB
flat; VO = 2VRMS
S/N
d
Signal to noise ratio
distortion
bass, treble at +12dB;
100
0.005
0.5
dB
%
a-weighted; VO = 2.6VRMS
VIN = 1VRMS; all stages 0dB
0.1
0.1
VOUT = 1VRMS; bass & treble =
12dB
%
SC
ET
Channel separation left/right
Total tracking error
0
-1
-2
100
0
dB
dB
dB
AV = 0 to -20dB
1
2
AV = -20 to -60dB
0
1. If configured as multiplexer-output
2. The SM Pin is active low (mute = 0)
3. If configured as pause-output
4. If programmed as subwoofer diff. output
Table 3.
Symbol
Absolute maximum ratings
Parameter
Value
10.5
Unit
VS
Operating supply voage
Operating tempeature range
Storage temperature range
V
°C
°C
V
Tamb
Tstg
-40 to 85
-55 to +150
2000
VESD
VES
ESD protection (human body mode)
ESD protection (machine mode)
200
V
Tble 4.
Symbol
Thermal data
Parameter
Value
Unit
Rth j-pins Thermal resistance junction-pins max
65
°C/W
Table 5.
Symbol
Supply
Parameter
Test condition
Min.
Typ.
Max.
Unit
VS
IS
Supply voltage
Supply current
7.5
35
9
10
65
V
VS = 9V
50
mA
Audioprocessor
(all Filters flat)
SVRR
Ripple rejection @ 1kHz
60
dB
14/69
TDA7402
Audioprocessor part
3
Audioprocessor part
3.1
Audioprocessor part features
●
Input multiplexer
–
–
–
–
–
–
–
2 fully differential CD stereo inputs with programmable attenuation
1 single ended stereo input
2 differential mono input
1 single ended mono input
In-gain 0..15dB, 1dB steps
internal offset cancellation (AutoZero)
separate second source selector
●
●
●
Beep
–
internal beep with 4 frequencies
Mixing stage
–
Beep, phone and navigation mixable to all speaker outputs
Loudness
–
–
–
programmable center frequency and frequency response
15 x 1dB steps
selectable flat-mode (constant atnuation)
●
●
●
Volume
–
–
–
0.5dB attenuator
100dB range
soft-step control with programmable times
Compander
–
dynmic range compression for use with CD
–
2:1 compression rate
–
programmable max. gain
Bass
–
–
–
–
2nd order frequency response
center frequency programmable in 8 steps
DC gain programmable
+ 15 x 1dB steps
●
●
Treble
–
–
–
2nd order frequency response
center frequency programmable in 4 steps
+15 x 1dB steps
Voice bandpass
–
–
–
2nd order butterworth highpass filter with programmable cut off frequency
2nd order butterworth lowpass filter with programmable cut off frequency
selectable flat mode
15/69
Audioprocessor part
TDA7402
●
Speaker
–
–
–
4 independent speaker controls in 1dB steps
control range 95dB
separate Mute
●
Subwoofer
–
–
–
–
single ended stereo output
independent stereo level controls in 1dB steps
control range 95dB
separate Mute
●
●
Mute Functions
–
–
direct mute
digitally controlled Soft Mute with 4 programmable mute-times
Pause Detector
programmable threshold
–
3.2
Input stages
In the basic configuration two full differential, two mono differential, one single ended stereo
and one single ended mono input are available. Iaddition a dedicated input for the stereo
decoder MPX signal is present.
Figure 3.
Input-stages
MAIN SOURCE
SELECTOR
SE3
FD1/SE2
FD2
SE2
FD1-
15K
15K
1
1
100K
MD1/SE4
MD2
MUTE
-
STEREO
IN GAIN
+
SE1
100K
FD1+
100K
AM
FM
15K
15K
15K
15K
SE3
FD2-
100K
1
-
STEREO
+
FD2+
100K
1
15K
15K
28K
MIXING
SELECTOR
MD2
MD1
FM
MUTE
SE4
28K
MIXING STAGE
MD1G
BEEP
100K
-
MONO
+
MD1
100K
SE4R
28K
28K
28K
28K
SE4R
MD2G
100K
SECOND SOURCE
SELECTOR
-
SE3
MONO
+
FD1/SE2
FD2
MD2
MD1/SE4
MD2
MUTE
28K
28K
100K
IN GAIN
SE1
SE1
AM
STEREO
100K
FM
AM
MONO
100K
NOISE BLANKER
+
STEREO DECODER
MPX
100K
D00AU1142
16/69
TDA7402
Audioprocessor part
3.2.1
Full differential stereo input 1 (FD1)
The FD1 input is implemented as a buffered full-differential stereo stage with 100kΩ input
impedance at each input. The attenuation is programmable in 3 steps from 0 to -12dB in
order to adapt the incoming signal level. A 6dB attenuation is included in the differential
stage, the additional 6dB are done by a following resistive divider. This input is also
configurable as two single ended stereo inputs (see pin-out).
3.2.2
3.2.3
3.2.4
3.2.5
Full differential stereo input 2 (FD2)
The FD2 input has the same general structure as FD1, but with a programmable attenuation
of 0 or 6dB embedded in the differential stage.
Mono differential input 1 (MD1)
The MD1 input is designed as a basic differential stage with 56kΩ input impedance. This
input is configurable as a single ended stereo input (see pin-out).
Mono differential input 2 (MD2)
The MD2 input has the same topology as MD1, but without the possibility to configure it to
single ended.
Single ended stereo input (SE1), singlended mono input (AM) and
FM-MPX input
All single ended inputs offer an input impedance of 100kΩ. The AM pin can be connected by
software to the input of the stereo-decoder in order to use the AM noiseblanker and AM High
Cut feature.
3.3
AutoZero
The AuZero allows a reduction of the number of pins as well as external components by
canceling any offset generated by or before the In-Gain-stage (Please notice that externally
generated offsets, e.g. generated through the leakage current of the coupling capacitors,
are not canceled).
The auto zeroing is started every time the DATA-BYTE 0 is selected and needs max. 0.3ms
for the alignment. To avoid audible clicks the Audioprocessor is muted before the loudness
stage during this time. The AutoZero feature is only present in the main signal path.
3.3.1
AutoZero for stereo decoder selection
A special procedure is recommended for selecting the stereo decoder at the main input-
selector to guarantee an optimum offset cancellation:
1. Soft Mute or Mute the signal-path
2. Temporary deselect the stereo decoder at all input selectors
3. Configure the stereo decoder via IIC-Bus
4. Wait 1ms
5. Select the stereo decoder at the main input selector first
17/69
Audioprocessor part
TDA7402
The root cause of this procedure is, that after muting the stereo decoder (Step 1), the
internal stereo decoder filters have to settle in order to perform a proper offset cancellation.
3.3.2
AutoZero remain
2
In some cases, for example if the µP is executing a refresh cycle of the I C Bus
programming, it is not useful to start a new AutoZero action because no new source is
selected and an undesired mute would appear at the outputs. For such applications the
TDA7402 could be switched in the AutoZero Remain Mode (Bit 6 of the subaddress byte).
If this bit is set to high, the DATABYTE 0 could be loaded without invoking the AutoZero and
the old adjustment value remains.
3.4
Pause detector / MUX-output
The pin number 40 (Pause/MUX) is configurable for two different functions:
1. During pause detector OFF this pin is used as a mono output of the main input selector.
This signal is often used to drive a level/equalizer display on the caradio front panel.
2. During pause detector ON the pin is used to define the ticonstant of the detector by
an external capacitor. The pause detector is driven by the internal stereo decoder
outputs in order to use pauses in the FM signal for aernate frequency jumps. If the
signal level of both stereo decoder channels is outside the programmed voltage
window, the external capacitor is abruptly dharged. Inside the pause condition the
capacitor is slowly recharged by a constant current of 25µA. The pause information is
2
2
also available via I C Bus (see I Buprogramming).
3.4.1
3.4.2
Loudness
There are four parameters programmable in the loudness stage:
Attenuation
Figure 4 shows the attenuation as a function of frequency at f = 400Hz
P
Figure 4.
Loudness attenuation @ f = 400Hz.
P
0.0
-5.0
-10.0
dB
-15.0
-20.0
-25.0
10.0
100.0
1.0K
10.0K
Hz
18/69
TDA7402
Audioprocessor part
3.4.3
Peak frequency
Figure 5 shows the four possible peak-frequencies at 200, 400, 600 and 800Hz
Figure 5.
Loudness center frequencies @ Attn. = 15dB.
0.0
-5.0
dB
-10.0
-15.0
-20.0
10.0
100.0
1
10.0K
Hz
3.4.4
Loudness order
Different shapes of 1st and 2nd-order loudness
st
nd
Figure 6.
1 and 2 order loudness @ Attn. = 15dB, f =400Hz
P
0.0
-5.0
dB
-10.0
-15.0
-20.0
10.0
100.0
1.0K
10.0K
Hz
3.4.5
Flat mode
In flat mode the loudness stage works as a 0dB to -19dB attenuator.
19/69
Audioprocessor part
TDA7402
3.5
Soft Mute
2
The digitally controlled Soft Mute stage allows muting/demuting the signal with a I C bus
programmable slope. The mute process can either be activated by the Soft Mute pin or by
2
the I C-bus. This slope is realized in a special S-shaped curve to mute slow in the critical
regions (see Figure 7).
2
For timing purposes the Bit0 of the I C bus output register is set to 1 from the start of muting
until the end of de-muting.
Figure 7.
Soft Mute timing
1
EXT.
MUTE
+SIGNAL
REF
-SIGNAL
1
I2C BUS
OUT
D97AU634
Time
Note:
Please notice that a started mute actis always terminated and could not be interrupted
by a change of the mute -signal.
3.6
Soft Step volume
When the volumlevel is changed audible clicks could appear at the output. The root cause
of those clickcould either be a DC offset before the volume stage or the sudden change of
the enope of the audio signal. With the Soft Step feature both kinds of clicks could be
reduced to a minimum and are no more audible. The blend time from one step to the next is
programmable in four steps.
Figure 8.
Soft Step timing
VOUT
1dB
0.5dB
Time
SS Time
-0.5dB
-1dB
D00AU1170
Note:
For steps more than 0.5dB the Soft Step mode should be deactivated because it could
generate a hard 1dB step during the blend time.
20/69
TDA7402
Audioprocessor part
3.7
Bass
There are four parameters programmable in the bass stage:
3.7.1
Attenuation
Figure 9 shows the attenuation as a function of frequency at a center frequency of 80Hz.
Figure 9. Bass control @ f = 80Hz, Q = 1
C
15.0
10.0
5.0
dB
0.0
-5.0
-10.0
-15.0
10.0
100.0
1.0K
10.0K
Hz
3.7.2
Center frequency
Figure 10 shows the eight possible center frequencies 60, 70, 80, 90, 100, 130, 150 and
200Hz.
Figure 10. Bacenter frequencies @ gain = 14dB, Q = 1
15.0
12.5
10.0
7.5
dB
5.0
2.5
0.0
10.0
100.0
1.0K
10.0K
Hz
21/69
Audioprocessor part
TDA7402
3.7.3
Quality factors
Figure 11 shows the four possible quality factors 1, 1.25, 1.5 and 2.
Figure 11. Bass quality factors @ Gain = 14dB, f = 80Hz
C
15.0
12.5
10.0
7.5
5.0
2.5
0.0
10.0
100.0
1.0K
10.0K
3.7.4
DC mode
In this mode the DC-gain is increased y 4dB. In addition the programmed center
frequency and quality factor is decreaby 25% which can be used to reach alternative
center frequencies or quality factors.
Figure 12. Bass normal and DC Mode @ Gain = 14dB, f = 80Hz
C
15.0
12.5
10.0
7.5
5.0
2.5
0.0
10.0
100.0
1.0K
10.0K
Note:
The center frequency, Q and DC-mode can be set fully independently.
22/69
TDA7402
Audioprocessor part
3.8
Treble
There are two parameters programmable in the treble stage:
3.8.1
Attenuation
Figure 13. shows the attenuation as a function of frequency at a center frequency of
17.5kHz.
Figure 13. Treble control @ f = 17.5kHz
C
15.0
10.0
5.0
0.0
-5.0
-10.0
-15.0
10.0
100.0
1.0K
10.0K
3.8.2
Center frequency
Figure 14. shows the four possible center frequencies 10k, 12.5k, 15k and 17.5kHz.
Figure 14. reble center frequencies @ gain = 14dB
15.0
12.5
10.0
7.5
5.0
2.5
0.0
10.0
100.0
1.0K
10.0K
23/69
Audioprocessor part
TDA7402
3.9
Subwoofer application
Figure 15. Subwoofer application with LPF 80/120/160Hz and HPF 90/135/180Hz
0.0
-10.0
-20.0
dB
-30.0
-40.0
-50.0
10.0
100.0
1.0K
10.0K
Hz
Both filters, the lowpass and the highpass-filter, he butterworth characteristics so that their
cut off frequencies are not equal, but shifteby the factor 1.125 to get a flat frequency
response.
3.10
Voice band application
Figure 16. Voiceband application with HPF 300/450/600/750Hz and LPF 3k/6kHz
0.0
-10.0
-20.0
dB
-30.0
-40.0
-50.0
10.0
100.0
1.0K
10.0K
Hz
24/69
TDA7402
Audioprocessor part
3.11
Compander
Signal compression
A fully integrated signal compressor with programmable attack and decay times is present in
the TDA7402 (see Figure 17).
The compander consists of a signal level detection, an A/D Converter plus adder and the
normal Soft Step volume stage. First of all the left and the right InGain-signal is rectified,
respectively, and the logarithm is build from the summed signal. The following low-pass
smooth the output-signal of the logarithm amplifier and improves the low frequency
suppression. The low pass output-voltage then is A/D converted an added to the current
2
volume-word defined by the I C bus. Assuming reference level or higher at the compander
input, the output of the ADC is 0. At lower levels the voltage is increasing with 1Bit/dB. It is
obvious that with this configuration and a 0.5dB-step volume stage the compression rate is
fixed to 2:1 (1dB less at the input leads to 0.5dB less at the output).
The internal reference level of the compander is programmable in three steps from 0.5V
RMS
to 2V
. For a proper behavior of the compression circuit it is mandatry to have at a 0dB
RMS
input signal exactly the programmed reference level after the InGaintage. E.g. at a
configured reference-level of 0.5V the output of the InGaitage has to have also
RMS
0.5V
at 0dB source-signal (Usually the 0dB for CD is defined as the maximum possible
RMS
signal-level). To adapt the external level to the internal reference level the programmable
attenuation in the differential stages and the InGain can be used.
Figure 17. Compander block diagram
SOFT STEP VOLUME
INL
INL
OUTL
OUTR
OUTL
OUTR
INR
INR
8 Bit
6 Bit
8 Bit
IIC-BUS
VOLUME
CONTROL
ADDER
D
CLKATT
CLKREL
A
LIN
RIN
STEREO FULL
WAVE RECTIFIER
50Hz LOW-PASS
ANTI-CLIP
ENABLE
LOG
AMPL
+
-
+
AM
MPIN
CLPIN
INPUT
SELECT
D00AU1147
3.11.1
Anti-clipping
In a second application the compander-circuit can be used for a anti-clipping or limiting
function. In this case one of the dedicated inputs (AM or MPin) is connected directly to the
clip-detector of the power-amplifier. if no clipping is detected, the open-collector output of
the power-amplifier is highohmic and the input-voltage of the rectifier is V . The level
REF
detector interprets this as a very small signal and reacts with the maximum programmed
compander gain. In the application this gain has to be compensated by decreasing the
25/69
Audioprocessor part
TDA7402
volume with the same value in order to get the desired output-level. In clipping situation the
open collector current generates a voltage drop at the rectifier input, which forces the
compander to decrease the gain until the clipping disappears.
It is even possible to run the compression mode and the anti-clipping mode in parallel. In
this case the maximum compander gain should be set to 29dB.
3.11.2
Characteristic
To achieve the desired compression characteristic like shown below the volume has to be
decreased by 4dB.
Figure 18. Compander characteristic
0
-8dB
-10
2:1
Output Level
-20
-38dB
dB
-30
15B
-40
-50
-60
0
-10
0
-30
-40
-50
-60
dB
Input Level
2
3.11.3
I C bus timing
2
While the compander is working, a volume word coming from this stage is added to the I C
bus volume word, and the volume is changed with a soft slope between adjacent steps
(Soft Step stageAs mentioned in the description of this stage, it is not recommended to
change the vme during this slope. To avoid this while the compander is working and the
volume has to be changed, the compander hold-bit is implemented (Bit 7 in the subaddress
byte). The recommended timing for changing the volume during compander ON is the
following:
1. Set the compander hold bit
2. Wait the actual Soft Step time
3. Change the volume
4. Reset the compander hold bit
The Soft Step times are in compander ON condition automatically adapted to the attack time
of the compander. In the following table the related Soft Step times are shown:
Table 6.
Attack times vs. soft-step times
Attack time
Soft Step time
6ms
12ms
24ms
48ms
0.16ms
0.32ms
0.64ms
1.28ms
26/69
TDA7402
Audioprocessor part
3.12
AC coupling
In some applications additional signal manipulations are desired, for example surround
sound or more band equalizing. For this purpose an AC coupling is placed before the
2
speaker attenuator, which can be activated or internally shorted by the I C bus. In short
condition the input signal of the speaker attenuator is available at the AC outputs. The input
impedance of this AC Inputs is 50kΩ.
3.13
Output selector
The output-selector allows to connect the main- or the second-source to the front, rear and
subwoofer speaker attenuator, respectively. As an example of this programming the device
is able to connect via software the main source to the back (rear) and the second source to
the front (see Figure 17). In addition to this stage allows to setup different applications by
2
I C bus programming. Three examples are given in Figure 18, 19, and 20.
Figure 19. Output selector
ACOUT ACINF ACINR SWIN
MAIN SOURCE
LEFT CHANNEL
SPEAKER FRONT
SPEAKER REAR
VOICE BAND
BANDPASS
25K
25K
50K
50K
50K
MS MONO
MAIN SOURCE
RIGHT CHANNL
LOWPASS
SPEAKER SUBWOOFER
SECOND URCE
25K
25K
SEC.S MONO
OFF/ON FC
LEFT CHANNEL
D00AU1155
SECOND SOURCE
27/69
Audioprocessor part
TDA7402
3.14
Subwoofer
Several different applications are possible with the subwoofer circuit:
1. Subwoofer filter OFF
a) Main source stereo (AC coupled)
b) Second source stereo (DC coupled)
c) Main source mono differential (DC coupled)
d) Second source mono-differential (DC coupled)
2. Subwoofer filter ON
a) Main source mono differential (DC coupled)
b) Second source mono differential (DC coupled)
c) Center speaker mode (filtered mono signal at SWL, unfiltered mono signal at
SWR)
In all applications the phase of the output-signal can be configured to be 0° or 180°. In the
center speaker mode only at the filtered output the phase is changed.
Figure 20. Application 1 using internal highpass and moo low pass filter
PROGRAMMING
5/1xxxxxxx
7/xxxxx1xx
10/xxxx10xx
12/1010xxxx
220nF
220nF
ACR
ACINF
ACOUT
SWIN
MAIN SOURCE
LEFT CHANNEL
SPEAKER FRONT
SPEAKER REAR
VOICE BAND
BANDPASS
BASS-FILTER
25K
50K
50K
50K
MS MONO
25K
AIN SOURCE
IGHT CHANNEL
LOWPASS
SPEAKER SUBWOOFER
SECOND SOURCE
25K
25K
SEC.S MONO
OFF/ON FC
LEFT CHANNEL
D00AU1156
SECOND SOURCE
28/69
TDA7402
Audioprocessor part
Figure 21. Application 2 using internal highpass and external stereo low pass filter
EXTERNAL
LOWPASS
PROGRAMMING
5/0xxxxxxx
7/xxxxx1xx
10/xxxx11xx
12/1010xxxx
220nF
ACINF
ACOUT
ACINR
SWIN
MAIN SOURCE
LEFT CHANNEL
SPEAKER FRONT
SPEAKER REAR
VOICE BAND
BANDPASS
BASS-FILTER
25K
25K
50K
50K
50K
MS MONO
MAIN SOURCE
RIGHT CHANNEL
LOWPASS
SPEAKER SUBWOOFER
SECOND SOURCE
25K
25K
SEC.S MONO
OFF/ON FC
LEFT CHANNEL
D00AU1157
SECOND SOURCE
Figure 22. Application 3 using pure external filtering (e.g. DSP)
EXTERNAL
FILTERING
PROGRAMMING
5/1xxxxxxx
7/xxxxx0xx
10/xxxx11xx
12/1010xxxx
220nF
ACINF
220nF
220nF
ACINR
220nF
SWIN
ACOUT
MAIN SOU
LEFT NNEL
SPEAKER FRONT
SPEAKER REAR
VOICE BAND
BANDPASS
BASS-FILTER
25K
50K
50K
50K
MS MONO
25K
MAIN SOURCE
RIGHT CHANNEL
LOWPASS
SPEAKER SUBWOOFER
SECOND SOURCE
25K
25K
SEC.S MONO
OFF/ON FC
LEFT CHANNEL
D00AU1163
SECOND SOURCE
29/69
Audioprocessor part
TDA7402
3.15
Speaker attenuator and mixing
A mixing-stage is placed after each speaker attenuator and can be set independently to
mixing mode. Having a full volume for the mix signal the stage offers a wide flexibility to
adapt the mixing levels.
Figure 23. Output selector
VOLUME
+15/-79dB
1dB Step
FRONT
REAR
1
1
OUTF
OUTR
25K
FROM OUTPUT
SELECTOR
VOLUME
+15/-79dB
1dB Step
25K
25K
VOLUME
+15/-79dB
1dB Step
25K
FROM MIXING
SELECTOR
D00AU1164
3.16
Audioprocessor testing
During the testmode, which can be activated by setting bit D of the stereo decoder testing
0
byte and the audioprocessor testing byte, several internal signals are available at the FD2R
pin. During this mode the input resistance of 100kOhm is disconnected from the pin. The
internal signals available are shown in the data byte specification.
30/69
TDA7402
Stereo decoder part
4
Stereo decoder part
4.1
Stereo decoder part features
●
●
●
●
●
●
●
●
●
●
No external components necessary
PLL with adjustment free, fully integrated VCO
Automatic pilot dependent MONO/STEREO switching
Very high suppression of intermodulation and interference
Programmable roll off compensation
Dedicated RDS-Soft Mute
Highcut and stereo blend-characteristics programmable in a wide range
FM/AM noiseblanker with several threshold controls
Multipath-detector with programmable internal/external influence
2
I C-bus control of all necessary functions
4.2
Stereo decoder electrical characteristics
V = 9V, de-emphasis time constant = 50µs, MPX inut voltage V
= 500mV (75kHz
MPX
S
deviation), modulation frequency = 1kHz, input gn = 6dB, T
= 27°C, unless otherwise
amb
specified.
Table 7.
Symbol
Stereo decoder electrical characteristics
Parameter
MPX input level
Test condition
Input gain = 3.5dB
Min.
Typ.
Max.
Unit
Vin
Rin
0.5
100
3.5
11
1.25
130
4.5
Vrms
kΩ
dB
dB
dB
dB
dB
%
Input resistance
70
1.5
Gmin
Gmax
Gstep
SVRR
a
Min. input gain
Max. inpgain
8.5
12.5
3.25
Step resolution
1.75
2.5
55
Supply voltage ripple rejection
Max. channel separation
Total harmonic distortion
Vripple = 100mV, f = 1kHz
30
80
50
THD
fin=1kHz, mono
0.02
0.3
S+N
N
Signal plus noise to noise ratio
A-weighted, S = 2Vrms
91
dB
Mono/Stereo-switch
VPTHST1 Pilot threshold voltage
VPTHST0 Pilot threshold voltage
VPTHMO1 Pilot threshold voltage
VPTHMO0 Pilot threshold voltage
for stereo, PTH = 1
for stereo, PTH = 0
for mono, PTH = 1
for mono, PTH = 0
10
15
7
15
25
12
19
25
35
17
25
mV
mV
mV
mV
10
PLL
Δf/f
Capture range
0.5
%
31/69
Stereo decoder part
TDA7402
Unit
Table 7.
Symbol
Stereo decoder electrical characteristics (continued)
Parameter Test condition
Min.
Typ.
Max.
De-emphasis and highcut
VLEVEL >> VHCH
LEVEL >> VHCH
25
44
50
70
50
62.5
75
100
3
75
80
µs
µs
µs
µs
V
τDeempFM De-emphasis time constants FM
VLEVEL >> VHCH
VLEVEL >> VHCH
100
130
MFM
Highcut time constant multiplier FM VLEVEL << VHCL
VLEVEL >> VHCH
37.5
47
56
75
3.7
5
µs
µs
µs
µs
VLEVEL >> VHCH
τDeempAM De-emphasis time constants AM
V
LEVEL >> VHCH
VLEVEL >> VHCH
Highcut time constant multiplier AM VLEVEL << VHCL
REF5V Internal reference voltage
MAM
4.7
-1
5.3
1
V
Lmin
Lmaxs
LGstep
min. LEVEL gain
0
dB
dB
dB
max. LEVEL gain
5
6
7
LEVEL gain step resolution
see section 2.7
see on 2.8
0.2
0.4
0.6
%REF
5V
VSBLmin Min. voltage for mono
VSBLmax Max. voltage for mono
VSBLstep Step resolution
17
62
20
70
23
78
%REF
5V
see section 2.8
see section 2.8
see section 2.9
see section 2.9
see section 2.9
%REF
5V
1.6
37
3.3
42
5.0
47
%REF
5V
VHCHmin Min. voltage for NO highcut
VHCHmax Maxvoltage for NO highcut
VHCHstep Step resolution
%REF
5V
58
66
74
%REF
5V
4.2
8.4
12.6
15
29
17
33
19
37
%VHCH
VHCLmin Min. voltage for FULL high cut
VHCLmax Max. voltage for FULL high cut
see section 2.9
see section 2.9
%VHCH
%REF
5V
VHCLstep Step resolution
see section 2.9
2.1
40
4.2
6.3
Carrier and harmonic suppression at the output
α19
α38
α57
α76
Pilot signal f=19kHz
Subcarrier f=38kHz
Subcarrier f=57kHz
Subcarrier f=76kHz
50
75
62
90
dB
dB
dB
dB
32/69
TDA7402
Stereo decoder part
Table 7.
Symbol
Stereo decoder electrical characteristics (continued)
Parameter Test condition
Min.
Typ.
Max.
Unit
Intermodulation (Note 4.3.1)
α2
α3
fmod=10kHz, fspur=1kHz
mod=13kHz, fspur=1kHz
65
75
dB
dB
f
Traffic Radio (Note 4.3.2)
α57 Signal f=57kHz
SCA - Subsidiary Communications Authorization (Note 4.3.3)
α67 Signal f = 67kHz
ACI - Adjacent Channel Interference (Note 4.3.4)
70
75
dB
dB
α114
α190
Signal f=114kHz
Signal f=190kHz
95
8
dB
dB
4.3
Notes about the characteristics
4.3.1
Intermodulation suppression
V (signal)(kHz)
O
--------------------------------------------------------------
α2 =
α3 =
;f = (2 ⋅ 10kHz) – 19kHz
s
V (spurious)(at1kHz)
O
V (signal)(at1kHz)
O
--------------------------------------------------------------
;f = (3 ⋅ 13kHz) – 38kHz
s
V (spurious)(at1kHz)
O
measured wit: 91% pilot signal; fm = 10kHz or 13kHz.
4.3.2
4.3.3
Traffic radio (V.F.) suppression
V (signal)(at1kHz)
O
α57(V.W.F)= ---------------------------------------------------------------------------------------
V (spurious)(at1kHz ± 23kHz)
O
measured with: 91% stereo signal; 9% pilot signal; fm=1kHz; 5% subcarrier
(f=57kHz, fm=23Hz AM, m=60%)
SCA (subsidiary communications authorization)
V (signal)(at1kHz)
O
--------------------------------------------------------------
α67 =
;f = (2 ⋅ 38kHz) – 67kHz
s
V (spurious)(at1kHz)
O
measured with: 81% mono signal; 9% pilot signal; fm=1kHz; 10%SCA - subcarrier
(fS = 67kHz, unmodulated).
33/69
Stereo decoder part
TDA7402
4.3.4
ACI (adjacent channel interference)
V (signal)(at1kHz)
O
--------------------------------------------------------------
α114 =
α190 =
;f = 110kHz – (3 ⋅ 38kHz)
s
V (spurious)(at4kHz)
O
V (signal)(at1kHz)
O
--------------------------------------------------------------
;f = 186kHz – (5 ⋅ 38kHz)
s
V (spurious)(at4kHz)
O
measured with: 90% mono signal; 9% pilot signal; fm=1kHz; 1% spurious signal
(fS = 110kHz or 186kHz, unmodulated).
4.4
Noise blanker part
4.4.1
Noise blanker part features
●
●
●
●
●
●
●
●
AM and FM mode
internal 2nd order 140kHz high-pass filter for MPX path
internal rectifier and filters for AM-IF path
programmable trigger thresholds
trigger threshold dependent on high frequenoise with programmable gain
additional circuits for deviation and fiestrength dependent trigger adjustment
4 selectable pulse suppression tifor each mode
programmable noise rectifier charge/discharge current
All parameters measured in FM mode if not otherwise specified.
Table 8.
Symbol
Noise blanker electrical characteristics
Parameter
Test condition
Min.
Typ.
Max.
Unit
111
110
101
100
011
010
001
000
00
30
35
mVOP
mVOP
mVOP
mVOP
mVOP
mVOP
mVOP
mVOP
mVOP
mVOP
mVOP
mVOP
40
45
meas.with
VTR
Trigger threshold (1)
VPEAK=0.9V
50
55
60
65
260
220
180
140
01
Noise controlled
Trigger threshold
meas.with
VTRNOISE
VPEAK=1.5V
10
11
34/69
TDA7402
Stereo decoder part
Table 8.
Symbol
Noise blanker electrical characteristics (continued)
Parameter Test condition
VMPX=0mV
MPX=50mV, f=150kHz
Min.
Typ.
Max.
Unit
0.5
1.5
2
0.9
1.7
2.5
1.3
2.1
2.9
V
V
V
VRECT Rectifier voltage
V
VMPX=200mV, f=150kHz
11
10
01
00
0.5
0.9
1.7
2.5
0.9(off)
1.2
1.3
1.5
2.3
3.1
VOP
VOP
VOP
VOP
meas.with
Deviation dependent
rectifier voltage
VRECTDE
VMPX=500mV
(75kHz dev.)
2.0
V
2.8
meas.with
11
10
01
00
0.5
0.9
1.7
2.1
0.9(off)
1.4
1.3
1.5
2.3
3.1
V
V
V
V
Fieldstrength
VMPX=0mV,
VLEVEL<< VSBL
(fully mono)
VRECTFS controlled rectifier
voltage
1.9
2.4
00
01
10
11
25.5
32
µs
µs
µs
µs
Signal HOLDN in
testmode
TSFM
Suppression pulse duration FM
22
00
01
10
11
1.2
800
1.0
ms
µs
µs
µs
Signal HOLDN in
testmode
TSAM
Suppression pulse duration AM
640
00
01
10
11
0.3
0.8
1.3
2.0
VRECTAD Noise rectifier discharge (2)
Signal PEAK in
testmode
V/ms
mV/µs
V/ms
adjustment
J
Noise rectifier (2)
0
1
10
20
Signal PEAK in
testmode
SRPEAK
charge
00
01
10
11
0.3
0.5
0.7
0.9
Noise rectifier adjustment
VADJMP
Signal PEAK in
testmode
trough multipath (2)
RAMIF AM IF Input resistance
35
50
6
65
kOhm
dB
G
G
G
min. gain AM IF
max. gain AM IF
step gain AM IF
AMIF,min
AMIF,max
AMIF,step
Signal AM-RECTIFIER in
Testmode
20
2
dB
dB
fAMIF,min min. fc AM IF
fAMIF,max max. fc AM IF
14
56
kHz
kHz
Signal AM-RECTIFIER in
Testmode
1. All thresholds are measured using a pulse with TR = 2 µs, THIGH= 2 µs and TF = 10 µs. The repetition rate must not
increase the PEAK voltage.
2. By design/characterization functionally guaranteed through dedicated test mode structure
35/69
Stereo decoder part
Figure 24. Vn timing diagram
TDA7402
V
in
V
op
D C
T im e
T
T
T
R
HIGH
F
Figure 25. Trigger threshold vs. V
PEAK
VTH
260m V (00)
220m V (01)
(10)
40mV (11)
MIN. TRIG. THRESHOLD
NCONTR OLLED TRIG . THRESHOLD
65m V
30m V
8
STEPS
V
0.9V
1.5V
PEAK [V]
Figure 26. Deviation controlled trigger adjustment
V
PEAK
[V
]
OP
00
2.8
2.0
01
10
1.2
0.9
Detector off (11)
DEVIATION [KHz]
20
32.5
45
75
Figure 27. Field strength controlled trigger adjustment
V
PEAK
MONO
STEREO
»
3V
2.3V (00)
1.8V (01)
1.3V (10)
NOISE
0.9V
ATC_SB OFF (11)
noisy signal
good signal
E'
36/69
TDA7402
Stereo decoder part
4.5
Multipath detector
4.5.1
Multipath detector features
●
●
●
internal 19kHz band pass filter
programmable band pass and rectifier gain
selectable internal influence on stereo blend and/or Highcut
Table 9.
Symbol
Multipath detector electrical characteristics
Parameter
Test Condition
Min.
Typ.
Max.
Unit
Center frequency of
multipath-bandpass
Stereo decoder locked
on pilot tone
fCMP
19
kHz
G1
G2
G3
G4
G1
G2
G3
6
dB
dB
dB
dB
dB
dB
dB
12
18
7.6
4.6
0
GBPMP Bandpass gain
GRECTM
Rectifier gain
P
0.25
0.5
ICHMP Rectifier charge current
µA
IDISMP Rectifier discharge current
4
mA
Quality detector
00
01
10
11
0.70
0.85
1.00
1.15
A
Mupath influence factor
37/69
Functional description of stereo decoder
TDA7402
5
Functional description of stereo decoder
Figure 28. Block diagram of stereo decoder
DEMODULATOR
DEEMPHASIS
+ HIGHCUT
FM_L
FM_R
INGAIN
INFILTER
LP 80KHz
- PLOT CANC
- ROLL-OFF COMP.
- LP 25KHz
MPX
AM
3.5 ... 11dB
STEP 2.5dB
t=50.62..5.75,100μs
(37.5,47,56,75μs)
4.th ORDER
100K
100K
5 bits
PLL +
PILOT-DET.
HC
CONTROL
REF 5V
SB CONTROL
D
VHCCH
VHCCL
F19
VSBL
A
F38
STEREO
MPSBINFL
NOISE BLANKER
LEVELSB-LP
LEVEL INPUT
GAIN 0..6dB
-
MPHCINFL
HOLDN
NOISE
LEVEL
AM-IF
MULTIPATH DET.
MPHCOUT
LEVELHC-LP
-
MPSBOUT
QUALITY
DETECTOR
+
QUAL
D00AU1135
MP-IN
MP-OUT
The stereo decoder-part of the TDA7402 (see Figure 28) contains all functions necessary to
demodulate the MPX-signal like pilot te pendent Mono/Stereo switching as well as
"stereo blend" and "highcut". Adaptatiolike programmable input gain, roll off
compensation, selectable de-emphasis time constant and a programmable fieldstrength
input allow to use different IF devices.
5.1
Stereo decoder mute
The TD7402 has a fast and easy to control RDS mute function which is a combination of
the audoprocessor's Soft Mute and the high ohmic mute of the stereo decoder. If the stereo
deoder is selected and a Soft Mute command is sent (or activated through the SM-pin) the
stereo decoder will be set automatically to the high-ohmic mute condition after the audio-
signal has been softmuted. Hence a checking of alternate frequencies could be performed.
Additionally the PLL can be set to "Hold" mode, which disables the PLL input during the
mute time. To release the system from the mute condition simply the unmute command
must be sent: the stereo decoder is unmuted immediately and the audioprocessor is softly
unmuted. Figure 29 shows the output-signal V as well as the internal stereo decoder mute
O
signal. This influence of Soft Mute on the stereo decoder mute can be switched off by setting
bit 3 of the Soft Mute byte to "0". A stereo decoder mute command (bit 0, stereo decoder
byte set to "1") will also set the stereo decoder independently to the high-ohmic mute state.
If any other source than the stereo decoder is selected the decoder remains muted and the
MPX pin is connected to V to avoid any discharge of the coupling capacitor through
ref
leakage currents. No further mute command should be applied.
38/69
TDA7402
Functional description of stereo decoder
Figure 29. Signals during stereo decoder's Soft Mute
Figure 30. Signal control via Soft Mute pin
PLLHOLD
INFUENCE
MP-HOLD
PLL-HOLD
SOFTMUTE
IFLUCE
STDHMUTE
INFLUENCE
STDHMUTE
SOFTMUTE
INFLUENCE
SOFTMUTE
PIN
SOFTMUTE
IIC-BUS
MUTED
D00AU1165
5.2
5.3
InGain + infilter
The InGain stage allows adjustment of the MPX-signal to a magnitude of about 1V
rms
th
internally, which is the recommended value. The 4 order input filter has a corner frequency
of 80kHz and is used to attenuate spikes and noise, and acts as an anti-aliasing filter for the
following switch capacitor filters.
Demodulator
In the demodulator block, the left and the right channels are separated from the MPX signal.
In this stage the 19kHz pilot tone is cancelled. To reach a high channel separation the
2
TDA7402 offers an I C bus programmable roll-off adjustment which is able to compensate
for the lowpass behavior of the tuner section. If the tuner's attenuation at 38kHz is in a range
from 7.2% to 31.0%, the TDA7402 needs no external network in front of the MPX-pin. Within
this range, an adjustment to obtain at least 40dB channel separation is possible. The bits for
this adjustment are located together with the fieldstrength adjustment in one byte. This gives
the possibility to perform an optimization step during the production of the car radio, where
39/69
Functional description of stereo decoder
TDA7402
the channel separation and the fieldstrength control are trimmed. The setup of the stereo
blend characteristics which is programmable in a wide range is described in Chapter 5.8.
5.4
De-emphasis and highcut
The de-emphasis lowpass allows to choose a time constant between 37.5 and 100µs. The
highcut control range will be 2 x τ
or 2.7 x τ
dependent on the selected time
Deemp
Deemp
constant (see programming section). The bit D7 of the hightcut-byte will shift timeconstant
and range.
Inside the highcut control range (between VHCH and VHCL) the LEVEL signal is converted
into a 5 bit word which controls the lowpass time constant between τ
...3 (3.7) x τ
.
Deemp
Deemp
Thereby the resolution will remain always 5 bits independently of the absolute voltage range
between the VHCH and VHCL values. In addition the maximum attenuation can be fixed
between 2 and 10dB.
2
The highcut function can be switched off by I C bus (bit D , Highcut byte set to "0").
7
The setup of the highcut characteristics is described in Chapter 5.9
5.5
PLL and pilot tone detector
The PLL has the task to lock on the 19kHz pilot te during a stereo transmission to allow a
correct demodulation. The included pilot tone-detector enables the demodulation if the pilot
tone reaches the selected pilot tone thshld V
. Two different thresholds are
PTHST
available. The detector output (signal SEREO, see Figure 2: Block diagram) can be
2
checked by reading the status byte of the TDA7402 via I C-bus. During a Soft Mute the PLL
can be set into "Hold"-mode which freezes the PLL's state (bit D , Soft Mute byte). After
4
releasing the Soft Mute the PLL will again follow the input signal only by correcting the
phase error.
5.6
5.7
Fieldtrength control
Thfieldstrength input is used to control the highcut and the stereo blend function. In
addition the signal can be also used to control the noiseblanker thresholds and as input for
the multipath detector. These additional functions are described in sections 5.3 and 6.
EVEL input and gain
To suppress undesired high frequency modulation on the highcut- and stereo blend-control
signal the LEVEL signal is lowpass filtered firstly. The filter is a combination of a 1st order
RC lowpass at 53kHz (working as anti-aliasing filter) and a 1st-order switched capacitor
lowpass at 2.2kHz. The second stage is a programmable gain stage to adapt the LEVEL
signal internally to different IF devices (see Testmode section 5: LEVELHCC). The gain is
widely programmable in 16 steps from 0dB to 6dB (step=0.4dB). These 4 bits are located
together with the Roll-Off bits in the "Stereo decoder adjustment" byte to simplify a possible
adjustment during the production of the car radio. This signal controls directly the Highcut
stage whereas the signal is filtered again (fc=100Hz) before the stereo blend stage
(see Figure 35).
40/69
TDA7402
Functional description of stereo decoder
5.8
Stereo blend control
The stereo blend control block converts the internal LEVEL voltage (LEVELSB) into an
demodulator compatible analog signal which is used to control the channel separation
between 0dB and the maximum separation. Internally this control range has a fixed upper
limit which is the internal reference voltage REF5V. The lower limit can be programmed
between 20 and 70% of REF5V in 3.3% steps (see Figure 31 and 32).
To adjust the external LEVEL voltage to the internal range two values must be defined: the
LEVEL gain L and VSBL (see Figure 32). At the point of full channel separation the
G
external level signal has to be amplified that internally it becomes equal to REF5V. The
second point (e.g. 10dB channel sep.) is then adjusted with the VSBL voltage.
Figure 31. Internal stereo blend characteristics
The gain can be programmed through 4 bits in the "Stereo decoder adjustment" byte. All
necessary internal reference voltages like REF5V are derived from a bandgap circuit.
Therefore they have a temperature co-efficient near zero.
Figure 32. Relation between internal and external LEVEL voltages for setup of
stereo blend
INTERNAL
VOLTAGES
INTERNAL
VOLTAGES
SETUP OF VST
SETUP OF VMO
LEVEL INTERN
LEVEL INTERN
REF 5V
VSBL
REF 5V
LEVEL
70%
VSBL
20%
t
t
VMO
VST
VMO
VST
FIELDSTRENGHT VOLTAGE
D00AU1168
FIELDSTRENGHT VOLTAGE
5.9
Highcut control
The highcut control set-up is similar to the stereo blend control set up: the starting point
VHCH can be set with 2 bits to be 42, 50, 58 or 66% of REF5V whereas the range can be
set to be 17, 22, 28 or 33% of VHCH (see Figure 33).
41/69
Functional description of stereo decoder
Figure 33. Highcut characteristics
TDA7402
LOWPASS
TIME CONSTANT
3.7•τ
'
Deemp
DEEMPHASIS SHIFT ON
3•τDeemp
OFF
τDeemp
τ
'
Deemp
VHCL
VHCH
FIELDSTRENGHT
D00AU1169
42/69
TDA7402
Functional description of the noise blanker
6
Functional description of the noise blanker
In the automotive environment the MPX-signal as well as the AM signal is disturbed by
spikes produced by the ignition and other radiating sources like the wiper motor. The aim of
the noiseblanker part is to cancel the audible influence of the spikes. Therefore the output of
the stereo decoder is held at the actual voltage for a time between 22 and 38µs in FM (370
and 645µs in AM mode). The block diagram of the noise blanker is given in Figure 34.
Figure 34. Block diagram of the noise blanker
AM/FM
RECTIFIER +
140KHz HPF
AMIF
RECT
14-56KHz LPF
(1st. order)
(1st. order)
RECTIFIER
+
-
MONOFLOP
HOLDN
FM: 22 to 40μs
AM: 370 to 6400μs
VTH
+
+
140KHz HPF
(2nd. order)
MPX
THRESHOLD
NERATOR
PEAK
INTEGRATOR
DISCHARGE
CONTROL
ADDITIONAL
THRESHOLD
CONTROL
MPOUT
D00AU1132
In a first stage the spikes must be detected but to avoid a wrong triggering on high
frequency (white) noise a complex trigger control is implemented. Behind the trigger stage a
pulse former generates the "blanking"pulse
6.1
Trigger path FM
The incoming MPX signal is highpass-filtered, amplified and rectified. This second order
highpass filter has a corner-frequency of 140kHz. The rectified signal, RECT, is integrated
(lowpass filteredo generate a signal called PEAK. The DC-charge/discharge behavior can
be adjusted awell as the transient behavior (MP discharge control). Also noise with a
frequency 140kHz increases the PEAK voltage. The PEAK voltage is fed to a threshold
generator, which adds to the PEAK voltage a DC dependent threshold VTH. Both signals,
RECT and PEAK+VTH are fed to a comparator which triggers a re-triggerable monoflop.
The monoflop's output activates the sample and hold circuits in the signalpath for the
selected duration.
6.2
Noise controlled threshold adjustment (NCT)
There are mainly two independent possibilities for programming the trigger threshold:
1. the low threshold in 8 steps (bits D to D of the noiseblanker byte I)
1
3
2. and the noise adjusted threshold in 4 steps (bits D and D of the noiseblanker byte I,
4
5
see Figure 21).
The low threshold is active in combination with a good MPX signal without noise; the PEAK
voltage is less than 1V. The sensitivity in this operation is high.
If the MPX signal is noisy (low fieldstrength) the PEAK voltage increases due to the higher
noise, which is also rectified. With increasing of the PEAK voltage the trigger threshold
increases, too. This gain is programmable in 4 steps (see Figure 25).
43/69
Functional description of the noise blanker
TDA7402
6.3
Additional threshold control mechanism
6.3.1
Automatic threshold control by the stereo blend voltage
Besides the noise controlled threshold adjustment there is an additional possibility for
influencing the trigger threshold which depends on the stereo blend control.
The point where the MPX signal starts to become noisy is fixed by the RF part. Therefore
also the starting point of the normal noise-controlled trigger adjustment is fixed (Figure 27).
In some cases the behavior of the noiseblanker can be improved by increasing the threshold
even in a region of higher fieldstrength. Sometimes a wrong triggering occurs for the MPX
signal often shows distortion in this range which can be avoided even if using a low
threshold. Because of the overlap of this range and the range of the stereo/mono transition it
can be controlled by stereo blend. This increase of the threshold is programmable in 3 steps
or switched off.
6.3.2
Over deviation detector
If the system is tuned to stations with a high deviation the noiseblanr can trigger on the
higher frequencies of the modulation or distortion. To avoid thbehavior, which causes
audible noise in the output signal, the noiseblanker offers a deviation-dependent threshold
adjustment. By rectifying the MPX signal a further signal representing the actual deviation is
obtained. It is used to increase the PEAK voltage. Offset and gain of this circuit are
programmable in 3 steps with the bits D and D the noiseblanker byte I (bit combination
6
7
'00' turns off the detector, see Figure 26).
6.3.3
6.3.4
Multipath level
To react on high repetitive spikes caused by a multipath-situation, the discharge time of the
PEAK voltage can be decreased depending on the voltage-level at pin MPout. The TDA7402
offers a linear as well as a threshold driven control. The linear influence of the multipath level
on the PEAK-sigal (D of multipath control byte) gives a discharge slew rate of 1V/ms .
The second ssibility is to activate the threshold driven discharge which switches on the
(a)
7
18kOhdischarge if the multipath level is below 2.5V (D of noiseblanker byte II byte).
7
AM mode of the noiseblanker
The TDA7402 noiseblanker is also suitable for AM noise cancelling. The detector uses in
AM mode the 450kHz unfiltered IF output of the tuner for spike detection. A combination of
programmable gain stage and lowpass filter forms an envelope detector which drives the
noiseblanker's input via a 120kHz 1st order highpass. In order to blank the whole spike in
AM mode the hold-times of the sample and hold circuit are much longer then in FM (640µs
to 1.2ms). All threshold controls can be used like in FM mode.
a. The serrate is measured with RDischarge = infinite and VMPout = 2.5 V.
44/69
TDA7402
Functional description of the multipath detector
7
Functional description of the multipath detector
Using the multipath detector the audible effects of a multipath condition can be minimized. A
multipath condition is detected by rectifying the spectrum around 19kHz in the fieldstrength
signal. An external capacitor is used to define the attack and decay times for the stereo
blend (see block diagram, Figure 34). Due to the very small charge currents this capacitor
should be a low leakage current type (e.g ceramic). Using this configuration an adaptation to
the user's requirement is possible without effecting the "normal" fieldstrength input (level) for
the stereo decoder. This application is given in Figure 34. Another (internal) time constant is
used to control the Highcut through the multipath detector
Selecting the "internal influence" in the configuration byte the stereo-blend and/or the
highcut is automatically invoked during a multipath condition according to the voltage
appearing at the MP_OUT pin.
Figure 35. Block diagram of the multipath detector
VDD
=
High-Cut-Infl.
Attach<500μs
Decay=2/10ms
to HCC
INT.
INFLUENCE
LOWPASS
100Hz
to SB
LOWPASS
53KHz
LOWPASS
2.2KHz
LEVEL
VDD
VDD
INT.
INFLUENCE
=
=
CHARGE
SHIFT
0 ... 1.5V
300μA
0.25μA/0.5μA
Stereoblend-Infl.
FAST
CHARGE
Attach=1ms
Decay=4/8s
MP HOLD
MP_OUT
470nF
BANDPASS
19KHz
RECTIFIER
GAIN 2 bits
M_IN
D00AU1166
GAIN 2 bits
7.1
Quality detector
The TDA7402 offers a quality detector output which gives a voltage representing the FM
reception conditions. To calculate this voltage the MPX-noise and the multipath-detector
output are summed according to the following formula:
V
= 1.6 (V
-0.8 V)+ a (REF5V-V
).
Mpout
Qual
Noise
The noise-signal is the PEAK signal without additional influences (see the noiseblanker
description). The factor 'a' can by programmed to 0.7 .... 1.15. The output is a low
impedance output able to drive external circuitry as well as simply fed to an AD converter for
RDS applications.
45/69
Functional description of the multipath detector
TDA7402
7.2
Testmode
During the testmode, which can be activated by setting bit D and bit D of the stereo
0
1
decoder testing byte, several internal signals are available at the FD2R+ pin. During this
mode the input resistance of 100kOhm is disconnected from the pin. The internal signals
available are shown in the Data byte specification.
7.3
Dual MPX usage
7.3.1
Feature description
The TDA7402 is able to support a twin tuner concept via the Dual MPX Mode. In this
configuration the MPX pin and the MD2G pin are acting as MPX1 and MPX2 inputs. The DC
voltage at the MD2 pin controls whether one or both MPX signals are used to decode the
stereo FM signal. It is designed as a window comparator with the characteristic shown in
Figure 3 (Please note that the thresholds have a hysteresis of 500mV).
In this mode the stereo decoder high ohmic-mute mutes both inputs parallel.
Figure 36. Dual MPX input diagram
MPX/
MPX1
1
100K
100K
40K
INGAIN
3.5...11dB
step 2.5dB
MD2G/
MPX2
1
1
CONTROL
CIRCUITRY
2/
CONROL
D00AU1167
7.3.2
Configuration
The Dual MPX mode can be easily configured by setting bit 3 of subaddress 30 to LOW (see
Byte 30 description and application diagram of Figure 38).
46/69
2
TDA7402
I C bus interface
2
8
I C bus interface
8.1
Interface protocol
●
●
●
●
●
●
The interface protocol comprises:
a start condition (S)
a chip address byte (the LSB bit determines read / write transmission)
a subaddress byte
a sequence of data (N-bytes + acknowledge)
a stop condition (P)
CHIP ADDRESS
SUBADDRESS
DATA 1....DATA n
TA
MSB
LSB
MSB
AZ
LSB
MSB
LSB
S
1
0
0
0
1
1
0
R/W ACK
C
I
A
A
A
A
A
ACK
ACK
P
S = Start
R/W = "0" -> Receive-Mode (Chip could be programmed by µP)
"1" -> Transmission-Mode (Data could be received by µP)
ACK = Acknowledge
P = Stop
Max clock speed 500kbits/s
8.2
8.3
Auto increment
If bit I in the subaddress byte is set to "1", the auto increment of the subaddress is enabled.
Transmitted data (send mode)
Table 10. Tansmitted data (send mode)
MSB
LSB
X
X
X
X
X
P
ST
SM
SM = Soft mute activated
ST = Stereo
P = Pause
X = Not Used
The transmitted data is automatically updated after each ACK.
Transmission can be repeated without new chipaddress.
A Power-On-Reset is invoked if the Supply voltage is below than 3.5V. After that the
following data is written automatically into the registers of all subaddresses:
Table 11. Reset condition
MSB
LSB
1
1
1
1
1
1
1
0
The programming after POR is marked bold-face / underlined in the programming tables.
With this programming all the outputs are muted to V (V = V /2).
REF
OUT
DD
47/69
2
I C bus interface
TDA7402
8.4
Subaddress (receive mode)
Table 12. Subaddress (receive mode)
MSB
LSB
A0
Function
I2
I1
I0
A4
A3
A2
A1
Compander hold
0
1
off
on
AutoZero remain
0
1
off
on
Auto Increment Mode
off
0
1
on
Subaddress
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Main Source Selector
Main Loudnes
Volume
Treble
Bas
ixing Programming
Soft Mute
Voice-Band
Second Source Selector
Second Source Loudness
Subwoofer Config. / Bass
Compander
Configuration Audioprocessor I
Configuration Audioprocessor II
Subwoofer attenuator L
Subwoofer attenuator R
Speaker attenuator LF
Speaker attenuator RF
Speaker attenuator LR
Speaker attenuator RR
Mixing Level Control
Testing Audioprocessor
stereo decoder
Noise-Blanker I
Noise-Blanker II
AM / AM-Noiseblanker
High-Cut Control
Fieldstr. & Quality
Multipath-Detector
stereo decoder Adjustment
Configuration stereo decoder
Testing Sterodecoder
48/69
2
TDA7402
I C bus interface
8.5
Data byte specification
The status after power on reset is marked bold face / underlined in the programming tables.
Table 13. Main selector (0)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
Source selector
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
FD1 / SE2
SE3
FD2
SE1
MD2
MD1 / SE4
Stereo decoder
AM
Input gain
0dB
0
0
:
0
0
:
0
0
:
0
1
:
1dB
:
1
1
1
1
1
1
0
1
14d
15dB
Mute
off
0
1
on
Table 14. Main loudness (1)
MSB
LSB
Function
D7
D6
5
D4 D3 D2 D1 D0
Attenuation
0 dB
-1 dB
:
0
0
:
0
0
:
0
0
:
0
0
:
0
1
:
0
0
:
1
1
:
1
1
:
1
1
:
0
1
:
-14 dB
-15 dB
:
1
:
0
:
0
:
1
:
1
:
-19 dB
not allowed
Center frequency
200Hz
0
0
1
1
0
1
0
1
400Hz
600Hz
800Hz
Loudness order
First order
0
1
Second order
49/69
2
I C bus interface
TDA7402
Table 15. Volume (2)
MSB
D7
LSB
D0
Attenuation
D6
D5 D4 D3 D2 D1
Gain/attenuation
(+32.0dB)
(+31.5dB)
:
0
0
:
0
0
:
0
0
:
0
0
:
0
0
:
0
0
:
0
0
:
0
1
:
0
0
0
:
0
0
0
:
0
0
0
:
1
1
1
:
1
1
1
:
0
0
0
:
0
0
1
:
0
1
0
:
+20.0dB
+19.5dB
+19.0dB
:
0
0
0
:
0
1
1
:
1
0
0
:
1
0
0
:
1
0
0
:
1
0
0
:
1
0
0
:
1
0
1
:
+0.5dB
0.0dB
-0.5dB
:
1
1
1
1
0
0
1
1
1
1
1
1
1
1
0
1
-79.0dB
-79.5dB
Note:
It is not recommended to use a gain more than 20dB for system performance reason. In
general, the maximum gain should be limited by software to the maximum value, which is
needed for the system.
Table 16. Treble filter (3)
MSB
D7
LSB
D0
Function
D6 D5 D4 D3 D2 D1
Treble steps
-15dB
-14dB
:
0
0
:
0
0
:
0
0
:
0
0
:
0
1
:
0
0
1
1
:
1
1
1
1
:
1
1
1
1
:
1
1
1
1
:
0
1
1
0
:
-1 dB
0 dB
0 dB
+1 dB
:
1
1
0
0
0
0
0
0
1
0
+14 dB
+15dB
Treble center frequency
10.0 kHz
0
0
1
1
0
1
0
1
12.5 kHz
15.0 kHz
17.5 kHz
Subwoofer + center speaker mode
0
On
Off
1
50/69
2
TDA7402
I C bus interface
Table 17. Bass filter (4)
MSB
LSB
D0
Function
D7
D6 D5 D4 D3 D2 D1
Bass steps
-15dB
-14dB
:
0
0
:
0
0
:
0
0
:
0
0
:
0
1
:
0
0
1
1
:
1
1
1
1
:
1
1
1
1
:
1
1
1
1
:
0
1
1
0
:
-1 dB
0 dB
0 dB
+1 dB
:
1
1
0
0
0
0
0
0
1
0
+14 dB
+15dB
Bass Q-factor
0
0
1
1
0
1
0
1
1.0
1.25
1.5
2.0
Bass DC-mode
0
Off
On
1
Table 18. Mixing programming (5)
MSB
LSB
D0
Function
D7
D6 D5 D4 D3 D2 D1
Mixing
0
Mute
1
enable
Mixing source
0
0
1
1
0
1
0
1
Beep
MD1
MD2
FM mono
Mixing target
0
Speaker LF off
Speaker LF on
Speaker RF off
Speaker RF on
Speaker LR off
Speaker LR on
Speaker RR off
Speaker RR on
1
0
1
0
1
0
1
Stereo subw. using internal highpass filter
0
On
Off
1
51/69
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I C bus interface
TDA7402
Table 19. Soft mute (6)
MSB
D7
LSB
D0
Function
D6 D5 D4 D3 D2 D1
Soft Mute
0
On (Mute)
1
Off
0
0
1
1
0
1
0
1
Mutetime = 0.48ms
Mutetime = 0.96ms
Mutetime = 123ms
Mutetime = 324 ms
Influence on stereo decoder highohmic mute
0
on
off
1
Influence on pilot detector old and MP hold
0
on
off
1
Influence on oft Mute
0
on
off
1
Beep frequencies
600 Hz
0
0
1
1
0
1
0
1
780 Hz
1.56 kHz
2.4 kHz
Table 20. Voiceband (7)
MSB
LSB
D0
Function
D7
D6 D5 D4 D3 D2 D1
Voice band low pass enable
0
Filter off
Filter on
1
Voice band low pass frequency
0
3 kHz
6 kHz
1
Voice band high pass enable
0
Filter off
Filter on
1
52/69
2
TDA7402
I C bus interface
Table 20. Voiceband (7) (continued)
MSB
D7
LSB
D0
Function
D6 D5 D4 D3 D2 D1
High pass cut off frequency
0
0
0
1
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
90Hz
135Hz
180Hz
215Hz
300Hz
450Hz
600Hz
750Hz
Anti clipping enable
0
on
off
1
Anti clipping inp
0
MP-In
AM
1
Table 21. Second source selector (8)
MSB
D7
LSB
D0
Function
D6 D5 D4 D3 D2 D1
Source selector
FD1 / SE2
SE3
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
FD2
SE1
MD2
MD1 / SE4
Stereo decoder
AM
Input gain
0dB
0
0
:
0
0
:
0
0
:
0
1
:
1dB
:
1
1
1
1
1
1
0
1
14dB
15dB
Mute
off
0
1
on
53/69
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I C bus interface
TDA7402
Table 22. Second loudness (9)
MSB
D7
LSB
Function
D6 D5 D4 D3 D2 D1 D0
Attenuation
0 dB
0
0
:
0
0
:
0
0
:
0
0
:
0
1
:
-1 dB
:
0
0
:
1
1
:
1
1
:
1
1
:
0
1
:
-14 dB
-15 dB
:
1
:
0
:
0
:
1
:
1
:
-19 dB
not allowed
Center frequency
200Hz
0
0
1
1
0
1
0
1
400Hz
600Hz
800Hz
Loudness order
First order
Second oder
0
1
Table 23. Subwoofer configuration / Bass (10)
MSB
D7
B
Function
D6 D5 D4 D3 D2 D1 D0
Subwoofer filter
off
0
0
1
1
0
1
0
1
80Hz
120Hz
160Hz
Subwoofer outputs
differential (mono)
single ended (stereo)
Subwoofer source
Second source
Main source
Subwoofer phase
180°
0
1
0
1
0
1
0°
Bass center frequency
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
60Hz
80Hz
70Hz
90Hz
100Hz
130Hz
150Hz
200Hz
54/69
2
TDA7402
I C bus interface
Table 24. Compander (11)
MSB
LSB
D0
Function
D7
D6 D5 D4 D3 D2 D1
Activity / reference level
0
0
1
1
0
1
0
1
off
0.5VRMS
1VRMS
2VRMS
Attack-times
6ms
0
0
1
1
0
1
0
1
12ms
24ms
49ms
Release-times
390ms
0
0
1
1
0
1
0
1
780ms
1.17s
1.56s
Soft tep-time1)
160µs
0
0
0
0
1
1
1
1
0
0
1
1
0
1
0
1
320µs
640µs
1.28ms
2.56ms
5.12ms
10.2ms
20.4ms
0
0
1
1
0
1
0
1
Compander max. gain
0
29dB
19dB
1
Note:
The Soft Step times are only programmable while the compander is not in use.
Table 25. Configuration audioprocessor I (12)
MSB
D7
LSB
Function
D6 D5 D4 D3 D2 D1 D0
Compander source
0
Main selector
1
Second source selector
Soft Step
0
off
on
1
55/69
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I C bus interface
TDA7402
Table 25. Configuration audioprocessor I (12) (continued)
MSB
D7
LSB
Function
D6 D5 D4 D3 D2 D1 D0
Main loudness
flat
0
1
Filter ON
Second loudness
flat
0
1
Filter ON
Front speaker
0
0
1
1
0
1
0
1
not allowed
Second source internal coupled
Main source AC coupled
Main source internal coupled
Rear speaker
0
0
1
1
0
1
0
1
not allowed
Second source nternal coupled
Main source AC coupled
Main source internal coupled
Table 26. Configuration audioprocessr II (13)
MSB
D7
LSB
D0
Function
D6 D5 D4 D3 D2 D1
Pause detector
0
off
on
1
Pause ZC window
160mV
0
0
1
1
0
1
0
1
80mV
40mV
not allowed
FD1 mode
single ended
differential
0
1
FD1 attenuation
0
0
1
1
0
1
0
1
-12dB
-6dB
-6dB
0dB
56/69
2
TDA7402
I C bus interface
Table 26. Configuration audioprocessor II (13) (continued)
MSB
D7
LSB
D0
Function
D6 D5 D4 D3 D2 D1
FD2 attenuation
0
-6dB
0dB
1
MD1 mode
single ended
differential
0
1
Table 27. Speaker, subwoofer and mixer level-control (14-20)
MSB
D7
LSB
Function
D6 D5 D4 D3 D2 D1 D0
1
:
0
:
0
:
0
:
1
:
1
:
1
:
1
:
+15 dB
:
1
1
0
0
:
0
0
0
0
:
0
0
0
0
:
0
0
0
0
:
0
0
0
0
:
0
0
0
0
:
0
0
0
0
:
1
0
0
1
+1 dB
0 dB
0 d
1 dB
:
0
0
:
0
0
:
0
0
:
0
1
:
1
0
:
1
0
:
1
0
:
1
0
:
-15 dB
-16 dB
:
0
0
1
1
0
0
0
0
1
1
1
1
1
1
0
1
-78 dB
-79 dB
x
1
x
x
x
x
x
Mute
Thprogramming of all speaker, subwoofer and mixing level controls are the same.
57/69
2
I C bus interface
TDA7402
Table 28. Testing Audioprocessor (21)
MSB
D7
LSB
Function
D6 D5 D4 D3 D2 D1 D0
Audioprocessor testmode
0
off
on
1
Test-multiplexer
Compander log amp. output
Compander low pass output
Compander DAC output
200kHz oscillator
not allowed
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
not allowed
NB-hold
internal reference
Compander testme
0
off
on
1
Cloc
0
external
nternal
1
AZ function
0
off
on
1
SC-clock
0
Fast mode
Normal mode
1
Note:
This byte is used for testing or evaluation purposes only and must not set to other values
than "11101110" in the application!
Table 29. Stereo decoder (22)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
0
STD unmuted
STD muted
1
0
0
1
1
0
1
0
1
IN-gain 11 dB
IN-gain 8.5 dB
IN-gain 6 dB
IN-gain 3.5 dB
0
Input AM pin
1
Input MPX pin
58/69
2
TDA7402
I C bus interface
Table 29. Stereo decoder (22) (continued)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
0
Forced MONO
1
MONO/STEREO switch automatically
0
Pilot threshold HIGH
Pilot threshold LOW
1
0
0
1
1
0
1
0
1
De-emphasis 50µs (37.5µs(1)
De-emphasis 62.5µs (46.9µs(1)
De-emphasis 75µs (56.3µs(1)
)
)
)
De-emphasis 100µs (75µs(1)
)
1. If De-emphasis-Shift enabled (Subaddr.26/Bit7 = 0)
Table 30. Noise blanker I (23)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
0
Noise blanker off
Noise blanker on
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Low threshold 65mV
Low threshold 60mV
Low threshold 55mV
Low threshold 50mV
Low threshold 45mV
Low threshold 40mV
Low threshold 35mV
Low threshold 30mV
0
0
1
1
0
1
0
1
Noise controlled threshold 320mV
Noise controlled threshold 260mV
Noise controlled threshold 200mV
Noise controlled threshold 140mV
0
0
1
1
0
1
0
1
Overdeviation adjust 2.8V
Overdeviation adjust 2.0V
Overdeviation adjust 1.2V
Overdeviation detector OFF
59/69
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I C bus interface
TDA7402
Table 31. Noiseblanker II (24)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
PEAK charge current
0
1
low
high
Fieldstrength adjust
0
0
1
1
0
1
0
1
2.3V
1.8V
1.3V
OFF
Blank Time FM / AM
38µs / 1.2ms
0
0
1
1
0
1
0
1
25.5µs / 800µs
32µs / 1.0s
22µs / 640µs
Noise rectifir discharge resistor
R = infine
0
0
1
1
0
1
0
1
RD= 56k
RDC = 33k
RDC = 18k
Strong multipath influence on PEAK 18k
0
off
1
on (18k discharge if VMPout< 2.5V)
Table 32. AM / FM noiseblanker (25)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
Stereo decoder mode
0
FM
AM
1
AM rectifier gain
6dB
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
8dB
10dB
12dB
14dB
16dB
18dB
20dB
60/69
2
TDA7402
I C bus interface
Table 32. AM / FM noiseblanker (25) (continued)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
Rectifier cut off frequency
14.0kHz
0
0
1
1
0
1
0
1
18.5kHz
28.0kHz
56.0kHz
1
1
must be "1"
Table 33. High cut (26)
MSB
LSB
Function
D7
D6
D5
D4 D3 D2 D1 D0
High cut
0
off
on
1
max. high cut
2dB
0
0
1
1
0
1
0
1
5dB
7dB
10dB
VHCH to be at
42% REF5V
50% REF5V
58% REF5V
66% REF5V
0
0
1
1
0
1
0
1
VHCL to be at
16.7% VHCH
22.2% VHCH
27.8% VHCH
33.3% VHCH
0
0
1
1
0
1
0
1
De-emphasis shift
0
On
Off
1
61/69
2
I C bus interface
TDA7402
Table 34. Fieldstrength control (27)
MSB
D7
LSB
D0
Function
D6
D5
D4 D3 D2 D1
VSBL to be at
20.0% REF5V
23.3% REF5V
26.6% REF5V
30.0% REF5V
33.3% REF5V
36.6% REF5V
40.0% REF5V
43.3% REF5V
46.6% REF5V
50.0% REF5V
53.3% REF5V
56.6% REF5V
60.0% REF5V
63.3% REFV
66.6% EF5V
70% REF5V
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Quality detector co-efficient
0
0
1
1
0
1
0
1
a=0.7
a=0.85
a=1.0
a=1.15
HCC level shift (only level through MPD)
0
0
1
1
0
1
0
1
0.0V
500mV
1.0 V
1.5 V
Table 35. Multipath detector (28)
MSB
LSB
Function
D7
D6
D5
D4 D3 D2 D1 D0
Fast Load
0
1
on
off
Bandpass Gain
6dB
0
0
1
1
0
1
0
1
12dB
16dB
18dB
62/69
2
TDA7402
I C bus interface
Table 35. Multipath detector (28) (continued)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
Rectifier gain
Gain = 7.6dB
Gain = 4.6dB
Gain = 0dB
disabled
0
0
1
1
0
1
0
1
Charge current at MP out
0
0.25µA
0.50µA
1
Multipath on high cut decay time
0
2ms
1
10ms
Multipath influence on AK discharge
0
off
1
-1V/ms
Table 36. Stereo decoder adjustment (29)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
Roll off compensation
0
0
0
:
0
0
0
:
0
0
1
:
0
1
0
:
not allowed
7.2%
9.4%
:
0
:
1
:
0
:
0
:
13.7%
:
1
1
1
20.2%
1
1
1
:
0
0
0
:
0
0
1
:
0
1
0
:
not allowed
19.6%
21.5%
:
1
:
1
:
0
:
0
:
25.3%
:
1
1
1
1
31.0%
LEVEL gain
0
0
0
:
0
0
0
:
0
0
1
:
0
1
0
:
0dB
0.4dB
0.8dB
:
1
1
1
1
6dB
63/69
2
I C bus interface
TDA7402
Table 37. Stereo decoder configuration (30)
MSB
D7
LSB
Function
D6
D5
D4 D3 D2 D1 D0
Multipath influence on high cut
0
On
Off
1
Multipath influence on stereo blend
0
On
Off
1
Level input over multipath detector(1)
0
1
1
On
Off
1
x
x
Dual MPX mode
0
1
On
Off
1
1
1
1
1
must be "1"
1. Using the multipath time-constants for stereo bland and high cut
64/69
2
TDA7402
I C bus interface
Table 38. Testing stereo decoder (31)
MSB
D7
LSB
Function
D6
D5
D4
D3
D2
D1
D0
Main testmode
0
off
on
1
Stereo decoder testmode
0
off
on
1
Test signals
F228
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
NB threshold
Level for stereo blend
Pilot magnitude
VHCCL
Pilot threshold
VHCCH
REF5V
HOLDN
NB peak
AM rectifier
VCOCON; VCO control voltage
VSBL
Pilot threshold
Level for high cut
REF5V
Audioprocessor oscillator
0
Off
On
1
1
must be "1"
Note:
This byte is used for testing or evaluation purposes only and must not set to other values
than "11111100" in the application!
65/69
Application information
TDA7402
9
Application information
Figure 37. Application diagram (standard configuration)
OUTLF
OUTLR
OUTRF
OUTRR
OUTSWL
OUTSWR
OUTSSL
OUTLF
OUTLR
OUTRF
OUTRR
OUTSWL
OUTSWR
OUTSSL
220nF
220nF
220nF
220nF
220nF
220nF
220nF
220nF
220nF
220nF
220nF
220nF
470nF
SEL
SER
OUTSSR
MD2G
30
29
28
27
26
25
24
23
SEL
SER
1
OUTSSR
220nF
220nF
220nF
220nF
44
43
42
41
MD2G
MD2
2
MD2
FD1L+
FD1L-
FD1R+
FD1R-
FD2L+
FD2L-
FD2R+
FD2R-
AM
FD1L+
FD1L-
FD1R+
FD1R-
FD2L+
FD2L-
FD2R+
FD2R-
AM
3
MD1G
MD1
MD1G
4
MD1
5
MUX PAUSE
47nF
MUX
6
40
10μF
CREF
7
39
38
37
ACOUTL
ACOUTR
ACOUTL
ACOUTR
8
9
2
SWINR
SWINL
36
35
10
11
13
16
220nF
470nF
470nF
ACINLF
ACINLR
ACINRF
ACINRR
34
33
32
31
MPX
MPX1
MPOUT
12
14
15
17
18
19
21
22
AMIF LEVEL
MPIN
QUAL
SM
GN
SDA
SCL
VDD
=
+
-
VB1
220nF
100nF
9
D00AU1161
AMIF
LEVEL
MPIN
QUAL SMUTE
SDA
SCL
Figure 38. Application diagram (Dual MPX mode)
OUTLF
OUTRF
OUTLR
OUTRR
OUTSWL
OUTSWR
OUTSSL
OUTLF
OUTLR
OUTRF
OUTRR
OUTSWL
OUTSWR
OUTSSL
100nF
220nF
220nF
220nF
220nF
220nF
220nF
220nF
220nF
100nF
100nF
470nF
SEL
SER
30
29
28
27
26
25
24
L
SER
1
OUTSSR
MD2G
MD2
23
44
43
42
OUTSSR
MPX2
100nF
2
FD1L+
FD1L-
FD1R+
FD1R-
FD2L+
FD2L-
FD2R+
FD2R-
AM
VPX CONTROL
MD1G
FD1L+
FD1L-
FD1R+
FD1R-
FD2L+
FD2L-
FD2R+
FD2R-
AM
3
220nF
220nF
MD1G
4
MD1
41
MD1
5
MUX PAUSE
47nF
MUX
40
39
6
10μF
CREF
7
ACOUTL
ACOUTR
38
37
ACOUTL
ACOUTR
8
9
220nF
SWINR
SWINL
36
35
10
11
13
16
220nF
470nF
470nF
ACINLF
ACINLR
ACINRF
ACINRR
34
33
32
31
MPX
MPX1
MPOUT
12
14
15
17
18
19
20
21
22
AMIF LEVEL
MPIN
QUAL
SM
GND
SDA
SCL
VDD
+
-
VB1
=
100nF
9
D00AU1158
AMIF
LEVEL
MPIN
QUAL SMUTE
SDA
SCL
66/69
TDA7402
Package information
10
Package information
®
In order to meet environmental requirements, ST (also) offers these devices in ECOPACK
®
packages. ECOPACK packages are lead-free. The category of second Level Interconnect
is marked on the package and on the inner box label, in compliance with JEDEC Standard
JESD97. The maximum ratings related to soldering conditions are also marked on the inner
box label.
ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com.
Figure 39. LQFP44 (10x10) mechanical data and package dimensions
mm
inch
DIM.
OUTLINE AND
MECHANICAL DATA
MIN.
TYP. MAX. MIN.
1.60
TYP. MAX.
0.0630
A
A1
A2
b
0.05
1.35
0.30
0.09
0.15 0.0020
0.0059
1.40
0.37
1.45 0.0531 0.0551 0.0571
0.45 0.0118 0.0146 0.0177
c
0.20 0.0035
0.0079
D
11.80 12.00 12.20 0.4646 0.4724 0.4803
9.80 10.00 10.20 0.3858 0.3937 0.4016
D1
D2
D3
E
2.00
0.0787
8.00
0.3150
11.80 12.00 12.20 0.4646 0.4724 0.4803
9.80 10.00 10.20 0.3858 0.3937 0.4016
E1
E2
E3
e
2.00
0.0787
8.00
0.80
0.60
1.00
0.31
0.0315
L
0.45
0.75 0.0177
0.0295
0.0039
L1
K
0.0394
3.5˚(min.),7˚(max.)
0.10
ccc
LQFP44 (10 x 10 x 1.40mm)
Exposed Pad Down
Note: 1. The ize of exposed pad is variable depending of lead-
fresign pad size. End user should verify “D2” and
E2” dimensions for each device application.
7278839 C
67/69
Revision history
TDA7402
11
Revision history
Table 39. Document revision history
Date
Revision
Changes
26-Apr-2002
21-Jun-2004
26-Apr-2004
26-Apr-2006
1
2
3
4
Initial release
Technical migration from ST-PRESS to EDOCS
Revalidation
Minor text changes.
Document reformatted.
23-Mar-2007
18-Sep-2008
5
6
Package change, text modifications.
Content of the Table 18, Table 19 and Table 24 reworked to improve
readability, no technical changes.
68/69
TDA7402
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