TDA7402TR

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 ■ Direct mute and Soft Mute ■ Internal beep ■ Four independent speaker-outputs Digital control ■ Stereo subwoofer output ■ ■ Independent second source-selector ■ Full mixing capability ■ Pause detector u d o LQFP44 r P e ) (s t c u Stereo decoder ■ RDS mute ■ No external adjustments ■ AM/FM noiseblanker with several trigger controls ■ Programmable multipath detector ■ Quality detector output s b O Table 1. d o r P e t e l o ) s ( ct t e l o I2C bus interface s b O 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 programming, especially for the adaptation to different IF devices. Device summary Order code Package Packing TDA7402 LQFP44 (10x 10x 1.4mm) Tray September 2008 Rev 6 1/69 www.st.com 1 Contents TDA7402 Contents 1 Pin connections and block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3 Audioprocessor part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.1 Audioprocessor part features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2 Input stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.3 3.4 Full differential stereo input 1 (FD1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2.2 Full differential stereo input 2 (FD2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2.3 Mono differential input 1 (MD1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2.4 Mono differential input 2 (MD2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2.5 Single ended stereo input (SE1), single ended mono input (AM) and FM-MPX input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 t e l o s b O AutoZero for stereo decoder selection . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.3.2 AutoZero remain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 ) (s Pause detector / MUX-output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 t c u 3.4.1 Loudness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.4.2 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Pr od 3.4.5 Peak frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Loudness order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Flat mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.5 Soft Mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.6 Soft Step volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.7 Bass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.8 2/69 r P e 3.3.1 3.4.4 s b O u d o AutoZero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.4.3 e t e ol ) s ( ct 3.2.1 3.7.1 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.7.2 Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.7.3 Quality factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.7.4 DC mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Treble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.8.1 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.8.2 Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.9 Subwoofer application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 3.10 Voice band application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 TDA7402 Contents 3.11 4 Compander . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.11.1 Anti-clipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.11.2 Characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.11.3 I2C 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 ) s ( ct Stereo decoder part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 u d o 4.1 Stereo decoder part features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.2 Stereo decoder electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.3 Notes about the characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.4 Intermodulation suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.3.2 Traffic radio (V.F.) suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.3.3 SCA (subsidiary communications authorization) . . . . . . . . . . . . . . . . . . 33 4.3.4 ACI (adjacent channel interference) . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 6 t c u Noise blanker part features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Multipath detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 d o r Multipath detector features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 P e Functional description of stereo decoder . . . . . . . . . . . . . . . . . . . . . . . 38 t e l o 5.1 Stereo decoder mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5.2 InGain + infilter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 5.3 Demodulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 5.4 De-emphasis and highcut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5.5 PLL and pilot tone detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5.6 Fieldstrength control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5.7 EVEL input and gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5.8 Stereo blend control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.9 Highcut control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 bs O ) (s s b O Noise blanker part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.5.1 5 t e l o 4.3.1 4.4.1 4.5 r P e Functional description of the noise blanker . . . . . . . . . . . . . . . . . . . . . 43 3/69 Contents 7 Trigger path FM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 6.2 Noise controlled threshold adjustment (NCT) . . . . . . . . . . . . . . . . . . . . . 43 6.3 Additional threshold control mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6.3.1 Automatic threshold control by the stereo blend voltage . . . . . . . . . . . . 44 6.3.2 Over deviation detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6.3.3 Multipath level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6.3.4 AM mode of the noiseblanker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 ) s ( ct 7.1 Quality detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 7.2 Testmode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 7.3 Dual MPX usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 u d o r P e 7.3.1 Feature description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 7.3.2 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 t e l o I2C bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 9 s b O 8.1 Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 8.2 Auto increment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 8.3 Transmitted data (send mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 8.4 Subaddress (receive mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 8.5 Data byte specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 ) (s t c u d o r Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 P e t e l o 10 s b O 4/69 6.1 Functional description of the multipath detector . . . . . . . . . . . . . . . . . 45 8 11 TDA7402 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 TDA7402 List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. 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 34. Table 35. Table 36. Table 37. Table 38. Table 39. 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 Audioprocessor (21). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Stereo decoder (22) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Noise blanker 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 ) s ( ct u d o r P e t e l o ) (s s b O t c u d o r P e s b O t e l o 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. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. Figure 39. Pin connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Input-stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Loudness attenuation @ fP = 400Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Loudness center frequencies @ Attn. = 15dB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1st and 2nd order loudness @ Attn. = 15dB, fP=400Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Soft Mute timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Soft Step timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Bass control @ fC = 80Hz, Q = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Bass center frequencies @ gain = 14dB, Q = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Bass quality factors @ Gain = 14dB, fC = 80Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Bass normal and DC Mode @ Gain = 14dB, fC = 80Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Treble control @ fC = 17.5kHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Treble center frequencies @ gain = 14dB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Subwoofer application with LPF 80/120/160Hz and HPF 90/135/180Hz . . . . . . . . . . . . . . 24 Voiceband application with HPF 300/450/600/750Hz and LPF 3k/6kHz . . . . . . . . . . . . . . 24 Compander block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Compander characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Output selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Application 1 using internal highpass and mono low pass filter . . . . . . . . . . . . . . . . . . . . . 28 Application 2 using internal highpass and external stereo low pass filter . . . . . . . . . . . . . . 29 Application 3 using pure external filtering (e.g. DSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Output selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Vn timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Trigger threshold vs. VPEAK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Deviation controlled trigger adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Field strength controlled trigger adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Block diagram of stereo decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Signals during stereo decoder's Soft Mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Signal control via Soft Mute pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Internal stereo blend characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Relation between internal and external LEVEL voltages for setup of stereo blend . . . . . . 41 Highcut characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Block diagram of the noise blanker. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Block diagram of the multipath detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Dual MPX input diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Application diagram (standard configuration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Application diagram (Dual MPX mode). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 LQFP44 (10x10) mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . 67 ) s ( ct u d o r P e t e l o ) (s t c u t e l o P e s b O 6/69 d o r s b O TDA7402 Pin connections and block diagram MD2G MD2 MD1G/SE4L MD1/SE4R MUX/PAUSE CREF ACOUTL ACOUTR SWINL SWINR ACINLF Pin connections (top view) 44 43 42 41 40 39 38 37 36 35 34 SE1L 1 33 ACINLR SE1R 2 32 ACINRF FD1L+/SE3L 3 31 ACINRR FD1L-/SE2L 4 30 OUTLF FD1R+/SE3R 5 29 OUTLR FD1R-/SE2R 6 28 OUTRF FD2L+ 7 27 OUTRR FD2L- 8 26 OUTSWL FD2R+ 9 25 OUTSWR 24 OUTSSL 23 OUTSSR 14 15 16 17 18 19 20 21 QUAL SM GND SDA SCL ) (s u d o 22 VDD 13 ) s ( ct r P e t e l o 12 MPOUT 11 MPIN 10 AM LEVEL FD2R- MPX Figure 1. AM IF 1 Pin connections and block diagram D00AU1131 s b O t c u d o r P e t e l o s b O 7/69 8/69 80KHz LP IN GAIN PILOT CANCELLATION PAUSE PIL. DET. MUTE TREBLE MPOUT 25KHz LP BASS AM/FM NOISE BANKER DIGITAL CONTROL HIGH CUT HP PULSE FORMER S&H A LEVEL D r P e MPIN MULTIPATH DETECTOR DEMODULATOR + STEREO ADJUST + STEREO BLEND LOUDNESS SOFT STEP VOLUME COMPANDER SOFT MUTE s b O PLL BEEP SECOND SOURCE SELECTOR ANTI CLIP. INPUT LOUDNESS LP VOICE BANDPASS ACOUTL u d o AM-IF AM PHONE + t e l o MPX SEN MD2G MIXING SELECTOR IN-GAIN + AUTO ZERO ) (s MD2 MD1G NAVI MAIN INPUTMULTIPLEXER MAIN SOURCE SELECTOR t c u MD1 SER SEL FD2R- FD2R+ AUX CHG d o r FD2L- FD2L+ FD1R- s b O FD1R+ SM ACINRR SWINL ACINRF SWINR QUAL. SUBWOOFER + PHONE CONTROL SW REAR OUTPUT SELECTOR FRONT ACIN OUTSWL OUTSWR MONO-FADER MONO-FADER SUPPLY D00AU1130 IIC BUS OUTRR CREF GND VDD QUAL SCL SDA OUTSSR OUTSSL OUTRF MONO-FADER OUTLR MIXER MONO-FADER OUTLF MONO-FADER ACINLF MONO-FADER Figure 2. FD1L- FD1L+ P e t e l o MUX Pin connections and block diagram TDA7402 Block diagram ACOUTR ) s ( ct ACINLR TDA7402 2 Electrical specifications Electrical specifications VS = 9V; Tamb = 25°C; RL = 10kΩ; all gains = 0dB; f = 1kHz; unless otherwise specified. Table 2. Electrical characteristics Symbol Parameter Test condition Min. Typ. Max. Unit 70 100 130 kΩ Input selector Rin Input resistance VCL Clipping level 2.2 2.6 SIN Input separation 80 100 Min. input gain -1 0 GIN MAX Max. input gain 13 15 GIN MIN GSTEP all single ended Inputs Step resolution P e Adjacent gain steps VDC -5 DC steps t e l o GMIN to GMAX Remaining offset with autozero Voffset Differential stereo inputs Rin Input resistance (see Figure 3) Differential du ro CMRR Common mode rejection ratio P e let eNO ct +1 dB 17 dB 1 1.5 dB 1 5 mV 6 10 mV 0.5 mV 70 100 130 kΩ -1 0 1 dB -5 -6 7 dB -11 -12 -13 dB VCM = 1VRMS @ 1kHz 46 70 dB VCM = 1VRMS @ 10kHz 46 60 dB ) (s ct Gain GCD s b O -10 (s) dB du ro 0.5 VRMS only at true differential input Output-noise @ speaker outputs 20Hz - 20kHz, flat; all stages 0dB 9 15 µV 72 kΩ Differential mono inputs o s b Rin O CMRR Input impedance Common mode rejection ratio Differential 40 56 VCM = 1VRMS @ 1kHz 40 70 dB VCM = 1VRMS @ 10kHz 40 60 dB Mix-gain = 6dB 250 350 500 mV fBeep1 570 600 630 Hz fBeep2 740 780 820 Hz fBeep1 1.48 1.56 1.64 kHz fBeep1 2.28 2.4 2.52 kHz Beep control VRMS fBeep Beep level Beep frequency 9/69 Electrical specifications Table 2. TDA7402 Electrical characteristics (continued) Symbol Parameter Test condition Min. Typ. Max. Unit Mixing control Mixing ratio MLEVEL Main / mix source -6/-6 dB GMAX Max. gain 13 15 17 dB AMAX Max. attenuation -83 -79 -75 dB ASTEP Attenuation step 0.5 1 1.5 dB 225 300 W Multiplexer output (1) ROUT Output impedance RL Output load resistance CL Output load capacitance VDC DC voltage level Step resolution AMAX Max. attenuation dB -21 -19 -17 dB 180 200 220 Hz 360 400 440 Hz 540 600 660 Hz 720 800 880 Hz 30 32 34 dB -83 -79.5 -75 dB 0 0.5 1 dB G = -20 to +20dB -0.75 0 +0.75 dB G = -80 to -20dB -4 0 3 dB 2 dB ) (s AMAX Max. attenuation ASTEP Step resolution o s b ET O VDC s b O d o r let EA t e l o t c u P e V 1.5 fP4 Max. gain 4.7 1 fP3 Volume control nF r P e fP2 Peak frequency GMAX u d o 4.5 10 0.5 fP1 fPeak kΩ 4.3 Loudness control ASTEP ) s ( ct 2 Attenuation set error Tracking error Adjacent attenuation steps 0.1 3 mV From 0dB to GMIN 0.5 5 mV DC steps Soft mute AMUTE TD VTH low Mute attenuation 80 dB T1 0.48 1 ms T2 0.96 2 ms Delay time Low threshold for SM T3 70 123 170 ms T4 200 324 600 ms 1 V Pin(2) VTH high High threshold for SM Pin 10/69 100 2.5 V TDA7402 Table 2. Electrical specifications Electrical characteristics (continued) Symbol Parameter RPU Internal pull-up resistor VPU Internal pull-up voltage Test condition Min. Typ. Max. Unit 32 45 58 kΩ 3.3 V Bass control CRANGE Control range ASTEP fC +14 +15 +16 dB 0.5 1 1.5 dB fC1 54 60 66 Hz fC2 63 70 77 Hz fC3 72 80 88 Hz fC4 81 90 99 Hz fC5 90 100 110 Hz fC6 117 130 143 Hz fC7 135 150 165 Hz 180 200 220 Hz 0.9 1 1.1 1.1 1.25 1.4 1.3 1.5 1.7 1.8 2 2.2 DC = off -1 0 +1 dB DC = on 4 4.4 6 dB +14 +15 +16 dB 0.5 1 1.5 dB fC1 8 10 12 kHz fC2 10 12.5 15 kHz fC3 12 15 18 kHz fC4 14 17.5 21 kHz Step resolution Center frequency e t e l fC8 Q1 QBASS O ) Q3 Q4 DCGAIN u d o Treble control ASTEP Pr Step resolution e t e ol s b O fC Pause s ( t c Bass-DC-gain CRANGE Control range o s b Q2 Quality factor Center frequency ) s ( t c u d o r P detector(3) VTH Zero crossing threshold IDELAY Pull-up current VTHP Pause threshold Window 1 40 mV Window 2 80 mV Window 3 160 mV 15 25 3.0 35 μA V 11/69 Electrical specifications Table 2. TDA7402 Electrical characteristics (continued) Symbol Parameter Test condition Min. Typ. Max. Unit Input impedance 35 50 65 kΩ GMAX Max. gain 14 15 16 dB AMAX Max. attenuation -83 -79 -75 dB ASTEP Step resolution 0.5 1 1.5 dB AMUTE Output mute attenuation 80 90 Speaker attenuator Rin Attenuation set error EE DC steps VDC Adjacent attenuation steps 0.1 Clipping level d = 0.3% RL Output load resistance CL Output load capacitance 2.2 dB 5 mV ) s ( t 2.6 o r P 2 2 c u d Audio outputs VCLIP dB VRMS kΩ 10 nF 30 100 W 4.3 4.5 4.7 V 81 90 99 Hz 122 135 148 Hz fHP3 162 180 198 Hz fHP4 194 215 236 Hz fHP5 270 300 330 Hz fHP6 405 450 495 Hz fHP7 540 600 660 Hz fHP8 675 750 825 Hz fLP1 2.7 3 3.3 kHz fLP2 5.4 6 6.6 kHz Input impedance 35 50 65 kΩ GMAX Max. gain 14 15 16 dB AATTN Max. attenuation -83 -79 -75 dB ASTEP Step resolution 0.5 1 1.5 dB AMUTE Output mute attenuation 80 90 ROUT Output impedance VDC DC voltage level so Voice bandpass fHP1 ) (s fHP2 Highpass corner frequency ete o r P ol s b O fLP ct du fHP e t e l Lowpass corner frequency b O Subwoofer attenuator Rin EE VDC 12/69 Attenuation set error DC steps Adjacent attenuation steps 1 dB 2 dB 5 mV TDA7402 Electrical specifications Table 2. Electrical characteristics (continued) Symbol Parameter Test condition Min. Typ. Max. Unit fLP1 72 80 88 Hz fLP2 108 120 132 Hz fLP3 144 160 176 Hz Subwoofer lowpass Lowpass corner frequency fLP Differential outputs(4) RL load resistance at each output RDL load resistance differential CLMAX Capacitive load at each output DC offset at pins ROUT Output impedance VDC DC voltage level eNO Output noise 1 kΩ 2VRMS; AC coupled; THD=1% 2 kΩ 1VRMS; AC coupled; THD=1% 2 2VRMS; AC coupled; THD=1% 4 CLmax between output terminals Output muted Compander ) (s Vi < -46dB GMAX VREF CF 10 nF 5 nF 10 mV 30 100 W 4.5 4.7 V 6 15 µV Pr -10 4.3 dB Vi < -46dB, Anti-clip = on 29 dB tAtt1 6 ms tAtt2 12 ms tAtt3 24 ms tAtt4 49 ms tRel1 390 ms tRel2 780 ms tRel3 1.17 s tRel4 1.56 s VREF1 Compander reference input-level VREF2 (equals 0dB) VREF3 0.5 VRMS 1.0 VRMS 2.0 VRMS Compression factor 0.5 ete Release time ct du o r P ol s b O tRel u d o kΩ 19 max. compander gain Attack time tAtt so b O Output muted e t e l ) s ( ct kΩ CLmax at each output to ground CDLMAX Capacitive load differential VOffset 1VRMS; AC coupled; THD=1% Output signal / input signal 13/69 Electrical specifications Table 2. TDA7402 Electrical characteristics (continued) Symbol Parameter Test condition Min. Typ. Max. Unit 3 10 15 20 µV µV General eNO BW = 20Hz - 20kHz output muted all gains = 0dB single ended inputs Output noise S/N Signal to noise ratio all gains = 0dB flat; VO = 2VRMS 106 bass, treble at +12dB; a-weighted; VO = 2.6VRMS 100 VIN = 1VRMS; all stages 0dB d distortion VOUT = 1VRMS; bass & treble = 12dB SC Channel separation left/right ET Total tracking error e t e ol AV = -20 to -60dB 1. If configured as multiplexer-output 2. The SM Pin is active low (mute = 0) 3. If configured as pause-output ) (s 4. If programmed as subwoofer diff. output Table 3. u d o 0.1 100 % % dB -1 0 1 dB -2 0 2 dB s b O Absolute maximum ratings t c u Symbol Parameter od Value Unit 10.5 V -40 to 85 °C -55 to +150 °C Operating supply voltage VS ct 0.1 0.05 Pr (s) dB 0.005 80 AV = 0 to -20dB dB Pr Tamb Operating temperature range Tstg Storage temperature range e t e ol VESD ESD protection (human body mode) ±2000 V VESD ESD protection (machine mode) ±200 V Value Unit 65 °C/W s b O Table 4. Thermal data Symbol Rth j-pins Table 5. Symbol Parameter Thermal resistance junction-pins max Supply Parameter Test condition VS Supply voltage IS Supply current VS = 9V Ripple rejection @ 1kHz Audioprocessor (all Filters flat) SVRR 14/69 Min. Typ. Max. Unit 7.5 9 10 V 35 50 65 mA 60 dB 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 – ● ● programmable center frequency and frequency response – 15 x 1dB steps – selectable flat-mode (constant attenuation) ) (s s b O – 0.5dB attenuator – 100dB range – soft-step control with programmable times t c u d o r Compander – dynamic range compression for use with CD P e t e l o ● t e l o – Volume ● ● r P e Beep, phone and navigation mixable to all speaker outputs Loudness ● s b O u d o internal beep with 4 frequencies Mixing stage – ● ) s ( ct – 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 ● ● ● ● 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 – 3.2 TDA7402 ) s ( ct u d o programmable threshold r P e Input stages t e l o In the basic configuration two full differential, two mono differential, one single ended stereo and one single ended mono input are available. In addition a dedicated input for the stereo decoder MPX signal is present. Figure 3. Input-stages FD1100K 1 u d o STEREO FD1+ ol ete bs O 15K MAIN SOURCE SELECTOR SE3 FD1/SE2 15K FD2 MD1/SE4 - MD2 + SE1 MUTE IN GAIN 100K AM 1 100K Pr )- s ( t c SE2 s b O 15K 15K 15K 15K FM SE3 FD2- 1 100K - STEREO + FD2+ 1 15K 100K 15K MIXING SELECTOR MD2 MD1 SE4 28K 28K MUTE FM MD1G MIXING STAGE BEEP 100K - MONO + MD1 28K 28K 28K 28K 100K SE4R SE4R MD2G 100K MONO SE3 FD1/SE2 28K MD1/SE4 FD2 MD2 100K SE1 STEREO SECOND SOURCE SELECTOR + 28K MD2 SE1 AM 100K FM AM MONO 100K MPX NOISE BLANKER + STEREO DECODER 100K D00AU1142 16/69 MUTE IN GAIN TDA7402 3.2.1 Audioprocessor part 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 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. 3.2.3 ) s ( ct 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). 3.2.4 u d o r P e Mono differential input 2 (MD2) The MD2 input has the same topology as MD1, but without the possibility to configure it to single ended. 3.2.5 t e l o s b O Single ended stereo input (SE1), single ended mono input (AM) and FM-MPX input ) (s 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. t c u d o r 3.3 AutoZero P e The AutoZero 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). t e l o bs O 3.3.1 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. AutoZero for stereo decoder selection A special procedure is recommended for selecting the stereo decoder at the main inputselector 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 In some cases, for example if the µP is executing a refresh cycle of the I2C 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 The pin number 40 (Pause/MUX) is configurable for two different functions: u d o 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 car radio front panel. 2. During pause detector ON the pin is used to define the time constant 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 alternate frequency jumps. If the signal level of both stereo decoder channels is outside the programmed voltage window, the external capacitor is abruptly discharged. Inside the pause condition the capacitor is slowly recharged by a constant current of 25µA. The pause information is also available via I2C Bus (see I2C Bus programming). r P e t e l o 3.4.1 ) (s Loudness s b O t c u There are four parameters programmable in the loudness stage: d o r 3.4.2 Attenuation Figure 4 shows the attenuation as a function of frequency at fP = 400Hz let P e Figure 4. so b O Loudness attenuation @ fP = 400Hz. 0.0 -5.0 -10.0 dB -15.0 -20.0 -25.0 10.0 18/69 ) s ( ct Pause detector / MUX-output 100.0 Hz 1.0K 10.0K TDA7402 3.4.3 Audioprocessor part 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 ) s ( ct -10.0 u d o -15.0 -20.0 10.0 t e l o 100.0 1.0K Hz 3.4.4 Loudness order ) (s r P e 10.0K s b O Different shapes of 1st and 2nd-order loudness t c u 1st and 2nd order loudness @ Attn. = 15dB, fP=400Hz Figure 6. d o r 0.0 P e t e l o s b O -5.0 dB -10.0 -15.0 -20.0 10.0 3.4.5 100.0 Hz 1.0K 10.0K Flat mode In flat mode the loudness stage works as a 0dB to -19dB attenuator. 19/69 Audioprocessor part 3.5 TDA7402 Soft Mute The digitally controlled Soft Mute stage allows muting/demuting the signal with a I2C bus programmable slope. The mute process can either be activated by the Soft Mute pin or by the I2C-bus. This slope is realized in a special S-shaped curve to mute slow in the critical regions (see Figure 7). For timing purposes the Bit0 of the I2C bus output register is set to 1 from the start of muting until the end of de-muting. Figure 7. Soft Mute timing EXT. MUTE 1 ) s ( ct u d o +SIGNAL REF r P e -SIGNAL t e l o 1 I2C BUS OUT bs D97AU634 Time Note: Please notice that a started mute action is always terminated and could not be interrupted by a change of the mute -signal. 3.6 Soft Step volume O ) s ( t c u d o When the volume level is changed audible clicks could appear at the output. The root cause of those clicks could either be a DC offset before the volume stage or the sudden change of the envelope 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. r P e t e l o s b O Figure 8. Soft Step timing VOUT 1dB 0.5dB Time SS Time -0.5dB -1dB D00AU1170 Note: 20/69 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. TDA7402 3.7 Audioprocessor part 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 @ fC = 80Hz, Q = 1 15.0 10.0 ) s ( ct 5.0 dB u d o 0.0 r P e -5.0 t e l o -10.0 -15.0 10.0 3.7.2 100.0 ) (s Center frequency s b O Hz 1.0K 10.0K Figure 10 shows the eight possible center frequencies 60, 70, 80, 90, 100, 130, 150 and 200Hz. t c u d o r Figure 10. Bass center frequencies @ gain = 14dB, Q = 1 15.0 b O so let P e 12.5 10.0 7.5 dB 5.0 2.5 0.0 10.0 100.0 Hz 1.0K 10.0K 21/69 Audioprocessor part 3.7.3 TDA7402 Quality factors Figure 11 shows the four possible quality factors 1, 1.25, 1.5 and 2. Figure 11. Bass quality factors @ Gain = 14dB, fC = 80Hz 15.0 12.5 10.0 7.5 ) s ( ct 5.0 u d o 2.5 r P e 0.0 10.0 3.7.4 t e l o 100.0 DC mode 1.0K 10.0K s b O In this mode the DC-gain is increased by 4.4dB. In addition the programmed center frequency and quality factor is decreased by 25% which can be used to reach alternative center frequencies or quality factors. ) (s t c u Figure 12. Bass normal and DC Mode @ Gain = 14dB, fC = 80Hz 15.0 d o r 12.5 P e t e l o s b O 10.0 7.5 5.0 2.5 0.0 10.0 Note: 22/69 100.0 1.0K The center frequency, Q and DC-mode can be set fully independently. 10.0K TDA7402 3.8 Audioprocessor part 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 @ fC = 17.5kHz 15.0 ) s ( ct 10.0 5.0 u d o 0.0 r P e -5.0 t e l o -10.0 -15.0 10.0 3.8.2 100.0 Center frequency ) (s s b O 1.0K 10.0K t c u Figure 14. shows the four possible center frequencies 10k, 12.5k, 15k and 17.5kHz. d o r Figure 14. Treble center frequencies @ gain = 14dB P e t e l o O bs 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 3.9 TDA7402 Subwoofer application Figure 15. Subwoofer application with LPF 80/120/160Hz and HPF 90/135/180Hz 0.0 -10.0 -20.0 dB ) s ( ct -30.0 u d o -40.0 -50.0 10.0 100.0 r P e Hz 1.0K 10.0K t e l o s b O Both filters, the lowpass and the highpass-filter, have butterworth characteristics so that their cut off frequencies are not equal, but shifted by the factor 1.125 to get a flat frequency response. ) 3.10 Voice band application s ( t c u d o r P e t e l o s b O 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 24/69 100.0 Hz 1.0K 10.0K TDA7402 3.11 Audioprocessor part 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 volume-word defined by the I2C 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). ) s ( ct u d o The internal reference level of the compander is programmable in three steps from 0.5VRMS to 2VRMS. For a proper behavior of the compression circuit it is mandatory to have at a 0dB input signal exactly the programmed reference level after the InGain-stage. E.g. at a configured reference-level of 0.5VRMS the output of the InGain stage has to have also 0.5VRMS at 0dB source-signal (Usually the 0dB for CD is defined as the maximum possible 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. r P e t e l o s b O Figure 17. Compander block diagram ) (s INL INR t c u d o r P e t e l o bs O SOFT STEP VOLUME INL OUTL OUTL INR OUTR OUTR 8 Bit IIC-BUS VOLUME CONTROL 8 Bit 6 Bit ADDER CLKATT CLKREL STEREO FULL WAVE RECTIFIER LIN ANTI-CLIP ENABLE D A 50Hz LOW-PASS RIN + 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 VREF. The level 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 ) s ( ct 0 -8dB -10 2:1 Output Level u d o -20 -38dB dB r P e -30 15dB -40 t e l o -50 -60 0 -10 s b O -20 -30 Input Level 3.11.3 ) (s I2C bus timing -40 -50 -60 dB t c u While the compander is working, a volume word coming from this stage is added to the I2C bus volume word, and the volume is changed with a soft slope between adjacent steps (Soft Step stage). As mentioned in the description of this stage, it is not recommended to change the volume 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: d o r P e t e l o bs O 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. 26/69 Attack times vs. soft-step times Attack time Soft Step time 6ms 0.16ms 12ms 0.32ms 24ms 0.64ms 48ms 1.28ms TDA7402 3.12 Audioprocessor part 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 speaker attenuator, which can be activated or internally shorted by the I2C 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 I2C bus programming. Three examples are given in Figure 18, 19, and 20. ) s ( ct Figure 19. Output selector ACOUT MAIN SOURCE t e l o bs O ) s ( t c 25K MS MONO u d o MAIN SOURCE 25K RIGHT CHANNEL r P e ACINR SWIN VOICE BAND BANDPASS LEFT CHANNEL r P e ACINF u d o 50K SPEAKER FRONT SPEAKER REAR 50K 50K LOWPASS SPEAKER SUBWOOFER SECOND SOURCE t e l o LEFT CHANNEL 25K SEC.S MONO OFF/ON FC 25K D00AU1155 SECOND SOURCE s b O 27/69 Audioprocessor part 3.14 TDA7402 Subwoofer Several different applications are possible with the subwoofer circuit: 1. 2. 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) 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) ) s ( ct u d o 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. r P e Figure 20. Application 1 using internal highpass and mono low pass filter t e l o PROGRAMMING 5/1xxxxxxx 7/xxxxx1xx 10/xxxx10xx 12/1010xxxx 220nF ACINF BASS-FILTER LEFT CHANNEL du e t e ol MAIN SOURCE RIGHT CHANNEL bs ACOUT ACINR O ) SPEAKER FRONT VOICE BAND BANDPASS 25K MS MONO SPEAKER REAR 50K 50K 28/69 50K 25K LOWPASS SECOND SOURCE s b O SWIN s ( t c MAIN SOURCE o r P 220nF SPEAKER SUBWOOFER 25K SEC.S MONO OFF/ON FC 25K LEFT CHANNEL D00AU1156 SECOND SOURCE 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 MAIN SOURCE ACOUT ACINR SWIN SPEAKER FRONT VOICE BAND BANDPASS BASS-FILTER LEFT CHANNEL SPEAKER REAR 25K 50K MS MONO 50K ) s ( ct 50K 25K MAIN SOURCE RIGHT CHANNEL u d o LOWPASS SPEAKER SUBWOOFER SECOND SOURCE 25K SEC.S MONO r P e OFF/ON FC 25K LEFT CHANNEL t e l o SECOND SOURCE D00AU1157 Figure 22. Application 3 using pure external filtering (e.g. DSP) 5/1xxxxxxx 7/xxxxx0xx 10/xxxx11xx 12/1010xxxx u d o MAIN SOURCE r P e b O so let MAIN SOURCE RIGHT CHANNEL )- s ( t c BASS-FILTER LEFT CHANNEL s b O EXTERNAL FILTERING PROGRAMMING 220nF 220nF 220nF ACINF ACOUT ACINR 220nF SWIN SPEAKER FRONT VOICE BAND BANDPASS SPEAKER REAR 25K MS MONO 50K 50K 50K 25K LOWPASS SECOND SOURCE SPEAKER SUBWOOFER 25K SEC.S MONO OFF/ON FC 25K LEFT CHANNEL D00AU1163 SECOND SOURCE 29/69 Audioprocessor part 3.15 TDA7402 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 FRONT VOLUME +15/-79dB 1dB Step 1 OUTF 25K FROM OUTPUT SELECTOR REAR VOLUME +15/-79dB 1dB Step FROM MIXING SELECTOR VOLUME +15/-79dB 1dB Step 1 r P e 25K t e l o 3.16 Audioprocessor testing ) (s OUTR u d o 25K 25K ) s ( ct D00AU1164 s b O During the testmode, which can be activated by setting bit D0 of the stereo decoder testing 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. t c u d o r P e t e l o s b O 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 ● I2C-bus control of all necessary functions ) s ( ct u d o r P e 4.2 Stereo decoder electrical characteristics t e l o VS = 9V, de-emphasis time constant = 50µs, MPX input voltage VMPX = 500mV (75kHz deviation), modulation frequency = 1kHz, input gain = 6dB, Tamb = 27°C, unless otherwise specified. Table 7. Stereo decoder electrical characteristics Symbol MPX input level Rin Input resistance Gmin Min. input gain Gmax Max. input gain O S+N N du P e let o s b THD ct Test condition Step resolution Supply voltage ripple rejection Min. Typ. Max. Unit 0.5 1.25 Vrms 70 100 130 kΩ 1.5 3.5 4.5 dB 8.5 11 12.5 dB 1.75 2.5 3.25 dB Input gain = 3.5dB ro Gstep a ) (s Parameter Vin SVRR s b O Vripple = 100mV, f = 1kHz Max. channel separation 30 55 dB 50 dB Total harmonic distortion fin=1kHz, mono 0.02 Signal plus noise to noise ratio A-weighted, S = 2Vrms 80 91 0.3 % dB Mono/Stereo-switch VPTHST1 Pilot threshold voltage for stereo, PTH = 1 10 15 25 mV VPTHST0 Pilot threshold voltage for stereo, PTH = 0 15 25 35 mV VPTHMO1 Pilot threshold voltage for mono, PTH = 1 7 12 17 mV VPTHMO0 Pilot threshold voltage for mono, PTH = 0 10 19 25 mV PLL Δf/f Capture range 0.5 % 31/69 Stereo decoder part Table 7. TDA7402 Stereo decoder electrical characteristics (continued) Symbol Parameter Test condition Min. Typ. Max. Unit VLEVEL >> VHCH 25 50 75 µs VLEVEL >> VHCH 44 62.5 80 µs VLEVEL >> VHCH 50 75 100 µs VLEVEL >> VHCH 70 100 130 µs De-emphasis and highcut τDeempFM De-emphasis time constants FM MFM Highcut time constant multiplier FM τDeempAM De-emphasis time constants AM VLEVEL > VHCH 37.5 VLEVEL >> VHCH 47 VLEVEL >> VHCH 56 VLEVEL >> VHCH 75 µs ) s ( t µs c u d µs 4.7 5 5.3 V -1 0 1 dB 5 6 7 dB 0.2 0.4 0.6 dB see section 2.8 17 20 23 %REF 5V see section 2.8 62 70 78 %REF 5V see section 2.8 1.6 3.3 5.0 %REF 5V see section 2.9 37 42 47 %REF 5V VHCHmax Max. voltage for NO highcut see section 2.9 58 66 74 %REF 5V VHCHstep Step resolution see section 2.9 4.2 8.4 12.6 %REF 5V VHCLmin Min. voltage for FULL high cut see section 2.9 15 17 19 %VHCH VHCLmax Max. voltage for FULL high cut see section 2.9 29 33 37 %VHCH VHCLstep Step resolution see section 2.9 2.1 4.2 6.3 %REF 5V 40 50 dB MAM REF5V Highcut time constant multiplier AM min. LEVEL gain Lmaxs max. LEVEL gain LGstep LEVEL gain step resolution VSBLmin Min. voltage for mono VSBLmax Max. voltage for mono VSBLstep Step resolution u d o Pr VHCHmin Min. voltage for NO highcut ete l o s O ) s ( t c e t e l o s b see section 2.7 o r P 3.7 Internal reference voltage Lmin b O VLEVEL