TDA7412 CARRADIO SIGNAL PROCESSOR ■ 3 STEREO INPUTS ■ 3 MONO INPUTS ■ DYNAMIC-COMPRESSION-STAGE FOR CD ■ SOFTSTEP-VOLUME ■ BASS, TREBLE AND LOUDNESS CONTROL ■ VOICE-BAND-FILTER ■ DIRECT MUTE AND SOFTMUTE ■ INTERNAL BEEP ■ FOUR INDEPENDENT SPEAKER-OUTPUTS ■ STEREO SUBWOOFER OUTPUT ■ INDEPENDENT SECOND SOURCESELECTOR Digital Control: ■ FULL MIXING CAPABILITY I2C-BUS INTERFACE ■ PAUSE DETECTOR TQFP44 ORDERING NUMBER: TDA7412 DESCRIPTION Stereodecoder: ■ RDS MUTE ■ NO EXTERNAL ADJUSTMENTS ■ AM/FM NOISEBLANKER WITH SEVERAL TRIGGER CONTROLS ■ PROGRAMMABLE MULTIPATH DETECTOR ■ QUALITY DETECTOR OUTPUT October 2003 The device includes a high performance audioprocessor and a stereodecoder-noiseblanker combination with the whole low frequency signal processing necessary for state-of-the-art as well as future carradios. The digital control allows a programming in a wide range of all the filter characteristics. Also the stereodecoder part offers several possibilities of programming especially for the adaptation to different IF-devices. 1/56 TDA7412 MD2G MD2 MD1G/SE4L MD1/SE4R MUX/PAUSE CREF ACOUTL ACOUTR SWINL SWINR ACINLF PIN CONNECTION (Top view) 44 43 42 41 40 39 38 37 36 35 34 FD1R+/SE3R 5 29 OUTLR FD1R-/SE2R 6 28 OUTRF FD2L+ 7 27 OUTRR FD2L- 8 26 OUTSWL FD2R+ 9 25 OUTSWR FD2R- 10 24 OUTSSL AM 11 23 OUTSSR 12 13 14 15 16 17 18 19 20 21 22 VDD OUTLF SCL 30 SDA 4 GND ACINRR FD1L-/SE2L SM ACINRF 31 QUAL 32 3 MPOUT SE1R FD1L+/SE3L MPIN ACINLR LEVEL 33 2 MPX 1 AM IF SE1L D00AU1131 ESD: All pins are protected against ESD according to the MIL883 standard. ABSOLUTE MAXIMUM RATINGS Symbol VS Parameter Value Unit 10.5 V -40 to 85 °C -55 to +150 °C Value Unit 65 °C/W Operating Supply Voltage Tamb Operating Temperature Range Tstg Storage Temperature Range THERMAL DATA Symbol Rth j-pins Parameter Thermal Resistance Junction-pins max SUPPLY Symbol Parameter Test Condition Min. Typ. Max. Unit 7.5 9 10 V 35 50 65 mA VS Supply Voltage IS Supply Current VS = 9V Ripple Rejection @ 1kHz Audioprocessor (all Filters flat) 60 dB Stereodecoder + Audioprocessor 55 dB SVRR 2/56 AM-IF MPX SEN MD2G MD2 MD1G MD1 SER SEL FD2R- FD2R+ FD2L- FD2L+ FD1R- FD1R+ FD1L- FD1L+ AM PHONE NAVI MAIN PLL BEEP SECOND SOURCE SELECTOR MIXING SELECTOR MAIN SOURCE SELECTOR 80KHz LP INPUTMULTIPLEXER AUX CHG IN GAIN + PILOT CANCELLATION PAUSE PIL. DET. MUTE IN-GAIN + AUTO ZERO MUX MPIN MPOUT MULTIPATH DETECTOR 25KHz LP SOFT STEP VOLUME COMPANDER SOFT MUTE DEMODULATOR + STEREO ADJUST + STEREO BLEND LOUDNESS ANTI CLIP. INPUT LOUDNESS SM AM/FM NOISE BANKER TREBLE PULSE FORMER S&H DIGITAL CONTROL BASS A LEVEL D HIGH CUT HP LP VOICE BANDPASS ACINRR SWINL ACINRF SWINR QUAL. SUBWOOFER + PHONE CONTROL SW REAR OUTPUT SELECTOR FRONT ACIN ACINLF SUPPLY D00AU1130 IIC BUS MONO-FADER CREF GND VDD QUAL SCL SDA OUTSSR OUTSSL OUTSWR OUTSWL OUTRR MONO-FADER OUTRF OUTLR OUTLF MONO-FADER MIXER MONO-FADER MONO-FADER MONO-FADER TDA7412 BLOCK DIAGRAM 3/56 ACINLR ACOUTR ACOUTL TDA7412 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 attenuation) Volume 0.5dB attenuator 100dB range soft-step control with programmable times Compander dynamic 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 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 SoftMute with 4 programmable mute-times Pause Detector 4/56 programmable threshold TDA7412 ELECTRICAL CHARACTERISTICS VS = 9V; Tamb = 25°C; RL = 10kΩ; all gains = 0dB; f = 1kHz; unless otherwise specified Symbol Parameter Test Condition Min. Typ. Max. Unit 70 100 130 kΩ INPUT SELECTOR Rin Input Resistance VCL Clipping Level 1.8 2.2 VRMS SIN Input Separation 80 100 dB GIN MIN Min. Input Gain -1 0 +1 dB GIN MAX Max. Input Gain 13 15 17 dB GSTEP Step Resolution 0.5 1 1.5 dB Adjacent Gain Steps -5 1 5 mV GMIN to GMAX -10 6 10 mV VDC Voffset DC Steps all single ended Inputs Remaining offset with AutoZero 0.5 mV DIFFERENTIAL STEREO INPUTS Rin GCD CMRR eNO Input Resistance (see Figure 1) Differential 70 100 130 kΩ Gain only at true differential input -1 0 1 dB -5 -6 7 dB -11 -12 -13 dB VCM = 1VRMS @ 1kHz 46 70 dB VCM = 1VRMS @ 10kHz 46 60 dB Common Mode Rejection Ratio Output-Noise @ Speaker-Outputs 20Hz - 20kHz, flat; all stages 0dB 9 15 µV 72 kΩ DIFFERENTIAL MONO INPUTS Rin CMRR Input Impedance Differential 40 56 Common Mode Rejection Ratio VCM = 1VRMS @ 1kHz 40 70 dB VCM = 1VRMS @ 10kHz 40 60 dB BEEP CONTROL VRMS Beep Level Mix-Gain = 6dB 250 350 500 mV fBeep Beep Frequency 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 MIXING CONTROL MLEVEL Mixing Ratio Main / Mix-Source -6/-6 dB 5/56 TDA7412 ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit GMAX Max. Gain 13 15 17 dB AMAX Max. Attenuation -83 -79 -75 dB ASTEP Attennuation Step 0.5 1 1.5 dB 225 300 Ω MULTIPLEXER OUTPUT 1 ROUT Output Impedance RL Output Load Resistance CL Output Load Capacitance VDC 2 DC Voltage Level kΩ 10 nF 4.3 4.5 4.7 V LOUDNESS CONTROL ASTEP Step Resolution 0.5 1 1.5 dB AMAX Max. Attenuation -21 -19 -17 dB fPeak Peak Frequency fP1 180 200 220 Hz fP2 360 400 440 Hz fP3 540 600 660 Hz fP4 720 800 880 Hz VOLUME CONTROL GMAX Max. Gain 30 32 34 dB AMAX Max. Attenuation -83 -79.5 -75 dB ASTEP Step Resolution 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 EA ET VDC Attenuation Set Error Tracking Error DC Steps Adjacent Attenuation Steps 0.1 3 mV From 0dB to GMIN 0.5 5 mV SOFT MUTE AMUTE TD VTH low 6/56 Mute Attenuation Delay Time Low Threshold for SM-Pin2 80 100 dB T1 0.48 1 ms T2 0.96 2 ms T3 70 123 170 ms T4 200 324 600 ms 1 V TDA7412 ELECTRICAL CHARACTERISTICS (continued) Symbol VTH high Parameter Test Condition Min. High Threshold for SM - Pin 2.5 RPU Internal pull-up resistor 32 VPU Internal pull-up Voltage Typ. Max. Unit V 45 58 3.3 kΩ V Notes: 1. If configured as Multiplexer-Output 2. The SM-Pin is active low (Mute = 0) BASS CONTROL CRANGE ASTEP fC QBASS DCGAIN Control Range +14 +15 +16 dB Step Resolution 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 fC8 180 200 220 Hz Q1 0.9 1 1.1 Q2 1.1 1.25 1.4 Q3 1.3 1.5 1.7 Q4 1.8 2 2.2 DC = off -1 0 +1 dB DC = on 4 4.4 6 dB Control Range +14 +15 +16 dB Step Resolution 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 Center Frequency Quality Factor Bass-DC-Gain TREBLE CONTROL CRANGE ASTEP fC Center Frequency 7/56 TDA7412 ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit PAUSE DETECTOR1 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 35 3.0 µA V SPEAKER ATTENUATORS Rin 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 EE VDC Attenuation Set Error DC Steps Adjacent Attenuation Steps 0.1 dB 2 dB 5 mV Notes: 1. If configured as Pause-Output AUDIO OUTPUTS VCLIP Clipping Level RL Output Load Resistance CL Output Load Capacitance ROUT Output Impedance VDC DC Voltage Level d = 0.3% 1.8 2.2 VRMS 2 kΩ 10 nF 30 100 Ω 4.3 4.5 4.7 V fHP1 81 90 99 Hz fHP2 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 VOICE BANDPASS fHP 8/56 Highpass corner frequency TDA7412 ELECTRICAL CHARACTERISTICS (continued) Symbol Min. Typ. Max. Unit 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 fLP Parameter Lowpass corner frequency Test Condition SUBWOOFER ATTENUATORS Rin EE VDC Attenuation Set Error DC Steps Adjacent Attenuation Steps dB 2 dB 1 5 mV SUBWOOFER Lowpass fLP Lowpass corner frequency fLP1 72 80 88 Hz fLP2 108 120 132 Hz fLP3 144 160 176 Hz Notes: 1. If programmed as Subwoofer Diff.-Output DIFFERENTIAL OUTPUTS1) RL RDL CLMAX load resistance at each output load resistance differential 1VRMS; AC coupled; THD=1% 1 kΩ 2VRMS; AC coupled; THD=1% 2 kΩ 1VRMS; AC coupled; THD=1% 2 kΩ 2VRMS; AC coupled; THD=1% 4 kΩ Capacitive load at each output CLmax at each Output to Ground 10 nF Capacitive load differential CLmax between Output terminals 5 nF VOffset DC Offset at pins Output muted 10 mV ROUT Output Impedance 30 100 Ω VDC DC Voltage Level 4.5 4.7 V eNO Output Noise 6 15 µV CDLMAX -10 4.3 Output muted Notes: 1. If programmed as Subwoofer Diff.-Output 9/56 TDA7412 ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit output muted all gains = 0dB single ended inputs 3 10 15 20 µV µV all gains = 0dB flat; VO = 2VRMS 106 dB bass, treble at +12dB; a-weighted; VO = 2.6VRMS 100 dB GENERAL eNO S/N d Output Noise Signal to Noise Ratio distortion SC Channel Separation left/right ET Total Tracking Error 10/56 BW = 20Hz - 20kHz VIN = 1VRMS ; all stages 0dB 0.005 0.1 % VOUT = 1VRMS ; Bass & Treble = 12dB 0.05 0.1 % 80 100 dB AV = 0 to -20dB -1 0 1 dB AV = -20 to -60dB -2 0 2 dB TDA7412 1.0 DESCRIPTION OF THE AUDIOPROCESSOR PART 1.1 Input stages In the basic configuration two full-differential, two mono-differential, one single ended stereo and one singleended mono input are available. In addition a dedicated input for the stereodecoder MPX-signal is present. Figure 1. Input-stages MAIN SOURCE SELECTOR SE3 FD1/SE2 SE2 15K FD1- 15K FD2 1 100K STEREO FD1+ - MD2 + SE1 IN GAIN 100K AM 1 100K MUTE MD1/SE4 15K 15K 15K 15K FM SE3 1 FD2100K - STEREO + 1 FD2+ 15K 100K 15K MIXING SELECTOR MD2 MUTE MD1 SE4 28K 28K MIXING STAGE FM MD1G 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 MUTE IN GAIN SE1 AM 100K FM AM MONO 100K MPX NOISE BLANKER + STEREO DECODER 100K D00AU1142 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). 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. 11/56 TDA7412 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), single-ended 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. 1.2 AutoZero 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). 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 AutoZerofeature is only present in the main signal-path. AutoZero for Stereodecoder-Selection A special procedure is recommended for selecting the stereodecoder at the main input-selector to guarantee an optimum offset-cancellation: (Step 0: SoftMute or Mute the signal-path) Step 1: Temporary deselect the stereodecoder at all input-selectors Step 2: Configure the stereodecoder via IIC-Bus Step 3: Wait 1ms Step 4: Select the stereodecoder at the main input-selector first The root cause of this procedure is, that after muting the stereodecoder (Step 1), the internal stereodecoder filters have to settle in order to perform a proper offset-cancellation. AutoZero-Remain In some cases, for example if the µP is executing a refresh cycle of the IIC-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 A679 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. 1.3 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 carradio 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 stereodecoder-outputs in order to use pauses in the FM-signal for alternate-frequency-jumps. If the signal-level of both stereodecoder 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 IIC-Bus (see IICBus programming). 12/56 TDA7412 1.4 Loudness There are four parameters programmable in the loudness stage: 1.4.1 Attenuation Figure 2 shows the attenuation as a function of frequency at fP = 400Hz Figure 2. Loudness Attenuation @ fP = 400Hz. 0.0 -5.0 -10.0 dB -15.0 -20.0 -25.0 10.0 100.0 1.0K 10.0K Hz 1.4.2 Peak Frequency Figure 3 shows the four possible peak-frequencies at 200, 400, 600 and 800HzFigure 3: Loudness Center frequencies @ Attn. = 15dB Figure 3. Loudness Center frequencies @ Attn. = 15dB. 0.0 -5.0 dB -10.0 -15.0 -20.0 10.0 100.0 1.0K 10.0K Hz 13/56 TDA7412 1.4.3 Loudness Order Different shapes of 1st and 2nd-Order Loudness Figure 4. 1st and 2nd Order Loudness @ Attn. = 15dB, fP=400Hz 0.0 -5.0 dB -10.0 -15.0 -20.0 10.0 100.0 Hz 1.0K 10.0K 1.4.4 Flat Mode In flat mode the loudness stage works as a 0dB to -19dB attenuator. 1.5 SoftMute The digitally controlled SoftMute stage allows muting/demuting the signal with a I2C-bus programmable slope. The mute process can either be activated by the SoftMute 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 5). For timing purposes the Bit0 of the I2C-bus output register is set to 1 from the start of muting until the end of demuting. Figure 5. Softmute-Timing EXT. MUTE 1 +SIGNAL REF -SIGNAL 1 I2C BUS OUT 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. 14/56 TDA7412 1.6 SoftStep-Volume and Speaker 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 audiosignal. With the SoftStep-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 6. SoftStep-Timing VOUT 1dB 0.5dB Time SS Time -0.5dB -1dB D00AU1170 Note: For steps more than 0.5dB (Volume) /1dB (speaker) the SoftStep mode should be deactivated because it could generate a hard 1dB step during the blend-time. 1.7 Bass There are four parameters programmable in the bass stage: 1.7.1 Attenuation Figure 7 shows the attenuation as a function of frequency at a center frequency of 80Hz. Figure 7. Bass Control @ fC = 80Hz, Q = 1 15.0 10.0 5.0 dB 0.0 -5.0 -10.0 -15.0 10.0 100.0 Hz 1.0K 10.0K 15/56 TDA7412 1.7.2 Center Frequency Figure 8 shows the eight possible center frequencies 60, 70, 80, 90, 100, 130, 150 and 200Hz. Figure 8. Bass center Frequencies @ Gain = 14dB, Q = 1 15.0 12.5 10.0 7.5 dB 5.0 2.5 0.0 10.0 100.0 Hz 1.0K 10.0K 1.7.3 Quality Factors Figure 9 shows the four possible quality factors 1, 1.25, 1.5 and 2. Figure 9. Bass Quality factors @ Gain = 14dB, fC = 80Hz 15.0 12.5 10.0 7.5 5.0 2.5 0.0 10.0 16/56 100.0 1.0K 10.0K TDA7412 1.7.4 DC Mode 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. Figure 10. Bass normal and DC Mode @ Gain = 14dB, fC = 80Hz 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. 1.8 Treble There are two parameters programmable in the treble stage: 1.8.1 Attenuation Figure 11 shows the attenuation as a function of frequency at a center frequency of 17.5kHz. Figure 11. Treble Control @ fC = 17.5kHz 15.0 10.0 5.0 0.0 -5.0 -10.0 -15.0 10.0 100.0 1.0K 10.0K 17/56 TDA7412 1.8.2 Center Frequency Figure 12 shows the four possible center frequencies 10k, 12.5k, 15k and 17.5kHz. Figure 12. Treble 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 1.9 Subwoofer Application Figure 13. 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 Hz 1.0K 10.0K Both filters, the lowpass- as well as the highpass-filter, have butterworth characteristic so that their cut-off frequencies are not equal but shifted by the factor 1.125 to get a flat frequency response. 18/56 TDA7412 1.10 Voice-Band Application Figure 14. 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 Hz 10.0K 1.11 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 IIC-Bus programming. In figure 18 to 20 three examples are given. Figure 15. Output Selector ACOUT MAIN SOURCE ACINF ACINR SWIN SPEAKER FRONT VOICE BAND BANDPASS LEFT CHANNEL SPEAKER REAR 25K MS MONO 50K 50K 50K MAIN SOURCE 25K RIGHT CHANNEL LOWPASS SPEAKER SUBWOOFER SECOND SOURCE 25K SEC.S MONO OFF/ON FC 25K LEFT CHANNEL D00AU1155 SECOND SOURCE 19/56 TDA7412 1.12 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-SpeakerMode only at the filtered output the phase is changed. Figure 16. Application1 using internal Highpass- and mono Low-pass-Filter PROGRAMMING 5/1xxxxxxx 7/xxxxx1xx 10/xxxx10xx 12/1010xxxx ACINF MAIN SOURCE BASS-FILTER LEFT CHANNEL 220nF 220nF ACOUT ACINR SWIN SPEAKER FRONT VOICE BAND BANDPASS SPEAKER REAR 25K MS MONO MAIN SOURCE RIGHT CHANNEL 50K 50K 50K 25K LOWPASS SECOND SOURCE SPEAKER SUBWOOFER 25K SEC.S MONO OFF/ON FC 25K LEFT CHANNEL D00AU1156 SECOND SOURCE 20/56 TDA7412 Figure 17. Application2 using internal Highpass- and external stereo Low-pass-Filter EXTERNAL LOWPASS PROGRAMMING 5/0xxxxxxx 7/xxxxx1xx 10/xxxx11xx 12/1010xxxx 220nF ACINF MAIN SOURCE BASS-FILTER LEFT CHANNEL ACOUT ACINR SWIN SPEAKER FRONT VOICE BAND BANDPASS SPEAKER REAR 25K MS MONO 50K 50K 50K 25K MAIN SOURCE RIGHT CHANNEL LOWPASS SPEAKER SUBWOOFER SECOND SOURCE 25K SEC.S MONO OFF/ON FC 25K LEFT CHANNEL D00AU1157 SECOND SOURCE Figure 18. Application3 using pure external Filtering (e.g. DSP) EXTERNAL FILTERING PROGRAMMING 5/1xxxxxxx 7/xxxxx0xx 10/xxxx11xx 12/1010xxxx MAIN SOURCE BASS-FILTER LEFT CHANNEL 220nF 220nF 220nF ACINF ACOUT ACINR 220nF SWIN SPEAKER FRONT VOICE BAND BANDPASS SPEAKER REAR 25K MS MONO MAIN SOURCE RIGHT CHANNEL 50K 50K 50K 25K LOWPASS SECOND SOURCE SPEAKER SUBWOOFER 25K SEC.S MONO OFF/ON FC 25K LEFT CHANNEL D00AU1163 SECOND SOURCE 21/56 TDA7412 1.13 Speaker-Attenuator and Mixing A Mixing-stage is placed after each speaker-attenuator and can be set independly to mixing-mode. Having a full volume for the Mix-signal the stage offers a wide flexibility to adapt the mixing levels. Figure 19. Output Selector FRONT VOLUME +15/-79dB 1dB Step 1 OUTF 1 OUTR 25K FROM OUTPUT SELECTOR REAR FROM MIXING SELECTOR VOLUME +15/-79dB 1dB Step VOLUME +15/-79dB 1dB Step 25K 25K 25K D00AU1164 1.14 Audioprocessor Testing During the Testmode, which can be activated by setting bit D0 of the stereodecoder 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. 2.0 STEREODECODER PART 2.1 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-Softmute ■ Highcut- and Stereoblend-characterisctics programmable in a wide range ■ FM/AMNoiseblanker with several threshold controls ■ Multipath-detector with programmable internal/external influence ■ I2C-bus control of all necessary functions 22/56 TDA7412 2.2 ELECTRICAL CHARACTERISTICS VS = 9V, deemphasis time constant = 50µs, MPX input voltage VMPX = 500mV (75kHz deviation), modulation frequency = 1kHz, input gain = 6dB, Tamb = 27°C, unless otherwise specified. Symbol Parameter Test Condition Min. Input Gain = 3.5dB Typ. Max. Unit 0.5 1.25 Vrms Vin MPX Input Level Rin Input Resistance 70 100 130 kΩ Gmin Min. Input Gain 1.5 3.5 4.5 dB Gmax Max. Input Gain 8.5 11 12.5 dB Gstep Step Resolution 1.75 2.5 3.25 dB SVRR Supply Voltage Ripple Rejection Vripple = 100mV, f = 1kHz 30 55 dB 50 dB a Max. Channel Separation THD Total Harmonic Distortion fin=1kHz, mono S+N N Signal plus Noise to Noise Ratio A-weighted, S = 2Vrms 80 91 0.02 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 ∆f/f Capture Range 0.5 % DEEMPHASIS and HIGHCUT τDeempFM Deemphasis Timeconstants FM MFM REF5V 25 50 75 µs VLEVEL >> VHCH 44 62.5 80 µs VLEVEL >> VHCH 50 75 100 µs VLEVEL >> VHCH 70 100 130 µs Highcut Timeconstant Multiplier FM VLEVEL << VHCL τDeempAM Deemphasis Timeconstants AM MAM VLEVEL >> VHCH 3 VLEVEL >> VHCH 37.5 µs VLEVEL >> VHCH 47 µs VLEVEL >> VHCH 56 µs VLEVEL >> VHCH 75 µs Highcut Timeconstant Multiplier AM VLEVEL << VHCL 3.7 Internal Reference Voltage 4.7 5 5.3 V 23/56 TDA7412 2.2 ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit Lmin min. LEVEL Gain -1 0 1 dB Lmaxs max. LEVEL Gain 5 6 7 dB LGstep LEVEL Gain Step Resolution see section 2.7 0.2 0.4 0.6 dB VSBLmin Min. Voltage for Mono see section 2.8 17 20 23 %REF5V VSBLmax Max. Voltage for Mono see section 2.8 62 70 78 %REF5V VSBLstep Step Resolution see section 2.8 1.6 3.3 5.0 %REF5V VHCHmin Min. Voltage for NO Highcut see section 2.9 37 42 47 %REF5V VHCHmax Max. Voltage for NO Highcut see section 2.9 58 66 74 %REF5V VHCHstep Step Resolution see section 2.9 4.2 8.4 12.6 %REF5V 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 %REF5V 40 50 dB Carrier and harmonic suppression at the output α19 Pilot Signal f=19kHz α38 Subcarrier f=38kHz 75 dB α57 Subcarrier f=57kHz 62 dB α76 Subcarrier f=76kHz 90 dB Intermodulation (Note 2.3.1) α2 fmod=10kHz, fspur=1kHz 65 dB α3 fmod=13kHz, fspur=1kHz 75 dB 70 dB 75 dB Traffic Radio (Note 2.3.2) α57 Signal f=57kHz SCA - Subsidiary Communications Authorization (Note 2.3.3) α67 Signal f = 67kHz ACI - Adjacent Channel Interference (Note 2.3.4) α114 Signal f=114kHz 95 dB α190 Signal f=190kHz 84 dB 24/56 TDA7412 2.3 NOTES TO THE CHARACTERISTICS 2.3.1 Intermodulation Suppression V O ( sign al ) ( a t1 kHz ) α 2 = --------------------------------------------------------------- ;f = ( 2 ⋅ 10kHz ) – 19kHz V O ( spu rio us ) ( at1kHz ) s V O ( sig nal ) ( a t1kHz ) α 3 = ---------------------------------------------------------------- ;f s = ( 3 ⋅ 13kH z ) – 38kH z V O ( sp urious ) ( at1kHz ) measured with: 91% pilot signal; fm = 10kHz or 13kHz. 2.3.2 Traffic Radio (V.F.) Suppression V O ( sig na l ) ( at1kHz ) α 57 ( V.W .F ) = ---------------------------------------------------------------------------------------V O ( spu riou s ) ( a t1kHz ± 23kHz ) measured with: 91% stereo signal; 9% pilot signal; fm=1kHz; 5% subcarrier (f=57kHz, fm=23Hz AM, m=60%) 2.3.3 SCA ( Subsidiary Communications Authorization ) V O ( sig nal ) ( at1kHz ) α67 = ---------------------------------------------------------------- ;f s = ( 2 ⋅ 38kH z ) – 67 kHz V O ( sp urious ) ( at1 kHz ) measured with: 81% mono signal; 9% pilot signal; fm=1kHz; 10%SCA - subcarrier ( fS = 67kHz, unmodulated ). 2.3.4 ACI ( Adjacent Channel Interference ) V O ( signa l ) ( at1kHz ) α 114 = ---------------------------------------------------------------- ;f s = 110 kHz – ( 3 ⋅ 38kHz ) V O ( spuriou s ) ( a t4 kHz ) V O ( signa l ) ( at1kHz ) α 190 = ---------------------------------------------------------------- ;f s = 186 kHz – ( 5 ⋅ 38kHz ) V O ( spuriou s ) ( a t4 kHz ) measured with: 90% mono signal; 9% pilot signal; fm=1kHz; 1% spurious signal ( fS = 110kHz or 186kHz, unmodulated). 2.4 NOISE BLANKER PART 2.4.1 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 frequency noise with programmable gain ■ additional circuits for deviation- and fieldstrength-dependent trigger adjustment 25/56 TDA7412 ■ 4 selectable pulse suppression times for each mode ■ programmable noise rectifier charge/discharge current 2.4.2 ELECTRICAL CHARACTERISTICS All parameters measured in FM mode if not otherwise specified. Symbol VTR VTRNOISE VRECT Parameter Trigger Threshold 1) noise controlled Trigger Threshold Rectifier Voltage Test Condition meas.with VPEAK=0.9V meas.with VPEAK=1.5V Min. Typ. Max. Unit 111 30 mVOP 110 35 mVOP 101 40 mVOP 100 45 mVOP 011 50 mVOP 010 55 mVOP 001 60 mVOP 000 65 mVOP 00 260 mVOP 01 220 mVOP 10 180 mVOP 11 140 mVOP VMPX=0mV 0.5 0.9 1.3 V VMPX=50mV, f=150kHz 1.5 1.7 2.1 V VMPX=200mV, f=150kHz 2 2.5 2.9 V VRECTDEV Deviation dependent Rectifier Voltage meas.with VMPX=500mV (75kHz dev.) 11 10 01 00 0.5 0.9 1.7 2.5 0.9(off) 1.2 2.0 2.8 1.3 1.5 2.3 3.1 VOP VOP VOP VOP VRECTFS Fieldstrength controlled Rectifier Voltage meas.with VMPX=0mV, VLEVEL<< VSBL (fully mono) 11 10 01 00 0.5 0.9 1.7 2.1 0.9(off) 1.4 1.9 2.4 1.3 1.5 2.3 3.1 V V V V TSFM Suppression Pulse Duration FM Signal HOLDN in Testmode 00 01 10 11 38 25.5 32 22 µs µs µs µs TSAM Suppression Pulse Duration AM Signal HOLDN in Testmode 00 01 10 11 1.2 800 1.0 640 ms µs µs µs VRECTADJ Noise rectifier discharge (2) adjustment Signal PEAK in Testmode 00 01 10 11 0.3 0.8 1.3 2.0 V/ms Noise rectifier (2) charge Signal PEAK in Testmode 0 1 10 20 mV/µs SRPEAK 26/56 TDA7412 2.4.2 ELECTRICAL CHARACTERISTICS (continued) Symbol VADJMP RAMIF Parameter Test Condition Noise rectifier adjustment through Multipath (2) Signal PEAK in Testmode Min. 00 01 10 11 AM IF Input resistance Signal AM-RECTIFIER in Testmode GAMIF,max max. gain AM IF GAMIF,step step gain AM IF fAMIF,min min. fc AM IF Signal AM-RECTIFIER in Testmode fAMIF,max max. fc AM IF Max. 0.3 0.5 0.7 0.9 35 GAMIF,min min. gain AM IF Typ. 50 Unit V/ms 65 kOhm 6 dB 20 dB 2 dB 14 kHz 56 kHz Notes: 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 V in V op DC T im e TR T HIGH TF Figure 20. Trigger Threshold vs. VPEAK V TH 2 6 0 mV (0 0 ) 2 2 0 mV (0 1 ) 1 8 0 mV (1 0 ) 1 4 0 mV (1 1 ) MIN . T R IG . T HR ES H OL D N O ISE C ON T R OL LE D T RIG . TH R ES H O LD 6 5 mV 8 STEPS 3 0 mV 0 .9 V 1.5 V V P EA K [V ] 27/56 TDA7412 Figure 21. Fig. 23: Deviation Controlled Trigger Adjustment VP E A K [V OP ] 00 2.8 01 2.0 10 1.2 0.9 D etector off (11) 20 3 2.5 45 D EV IA TIO N [KH z] 75 Figure 22. Fieldstrength Controlled Trigger Adjustment VPEAK MONO STEREO » 3V 2.3V (00) 1.8V (01) 1.3V (10) NOISE 0.9V ATC_SB OFF (11) noisy signal 28/56 good signal E' TDA7412 2.5 MULTIPATH Detector 2.5.1 Features: ■ internal 19kHz band-pass filter ■ programmable band-pass- and rectifier-gain ■ selectable internal influence on Stereoblend and/or Highcut 2.5.2 ELECTRICAL CHARACTERISTICS Symbol fCMP GBPMP Parameter Test Condition Min. Typ. Max. Unit Center frequency of MultipathBandpass stereodecoder locked on Pilottone 19 kHz Bandpass Gain G1 6 dB G2 12 dB G3 16 dB G4 18 dB G1 7.6 dB G2 4.6 dB G3 0 dB 0.25 0.5 µA 4 mA GRECTMP Rectifier Gain ICHMP Rectifier Charge Current IDISMP Rectifier Discharge Current QUALITY DETECTOR A Multipath Influence Factor 00 01 10 11 0.70 0.85 1.00 1.15 29/56 TDA7412 3.0 FUNCTIONAL DESCRIPTION OF STEREODECODER Figure 23. Block diagram of Stereodecoder DEEMPHASIS + HIGHCUT FM_L t=50.62..5.75,100µs (37.5,47,56,75µs) FM_R DEMODULATOR MPX 100K INGAIN INFILTER 3.5 ... 11dB STEP 2.5dB LP 80KHz 4.th ORDER - PLOT CANC - ROLL-OFF COMP. - LP 25KHz AM 5 bits PLL + PILOT-DET. 100K F19 REF 5V SB CONTROL VSBL HC CONTROL D A F38 VHCCH VHCCL STEREO MPSBINFL NOISE BLANKER - LEVELSB-LP AM-IF NOISE LEVEL INPUT MPHCINFL HOLDN GAIN 0..6dB MULTIPATH DET. MPHCOUT - LEVEL LEVELHC-LP MPSBOUT QUALITY DETECTOR + D00AU1135 MP-IN QUAL MP-OUT The stereodecoder-part of the A679 (see Fig. 23) contains all functions necessary to demodulate the MPX-signal like pilottone-dependent MONO/STEREO-switching as well as "stereoblend" and "highcut". Adaptations like programmable input gain, roll-off compensation, selectable deemphasis time constant and a programmable fieldstrength input allow to use different IF-devices. 3.1 Stereodecoder-Mute The A679 has a fast and easy to control RDS-Mute function which is a combination of the audioprocessor's SoftMute and the high-ohmic mute of the stereodecoder. If the stereodecoder is selected and a SoftMute command is sent (or activated through the SM-pin) the stereodecoder 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 stereodecoder is unmuted immediately and the audioprocessor is softly unmuted. Fig. 26 shows the output-signal VO as well as the internal stereodecoder mute signal. This influence of SoftMute on the stereodecoder mute can be switched off by setting bit 3 of the SoftMute byte to "0". A stereodecoder mute command (bit 0, stereodecoder byte set to "1") will set the stereodecoder in any case independently to the high-ohmic mute state. If any other source than the stereodecoder is selected the decoder remains muted and the MPX-pin is connected to Vref to avoid any discharge of the coupling capacitor through leakage currents. No further mute command should be applied. 30/56 TDA7412 Figure 24. Signals during stereodecoder's SoftMute Figure 25. Signal-Control via SoftMute-Pin PLL-HOLD INFLUENCE MP-HOLD PLL-HOLD SOFTMUTE INFLUENCE STDHMUTE INFLUENCE STDHMUTE SOFTMUTE INFLUENCE SOFTMUTE PIN IIC-BUS SOFTMUTE MUTED D00AU1165 3.2 InGain + Infilter The InGain stage allows to adjust the MPX-signal to a magnitude of about 1V rms internally which is the recommended value. The 4.th 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. 3.3 Demodulator In the demodulator block the left and the right channel are separated from the MPX-signal. In this stage also the 19-kHz pilottone is cancelled. For reaching a high channel separation the A679 offers an I2C-bus programmable roll-off adjustment which is able to compensate 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 A679 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 31/56 TDA7412 optimization step during the production of the carradio where the channel separation and the fieldstrength control are trimmed. The setup of the Stereoblend characteristics which is programmable in a wide range is described in 2.8. 3.4 Deemphasis and Highcut The deemphasis-lowpass allows to choose a time constant between 37.5 and 100µs. The highcut control range will be 2 x τDeemp or 2.7 x τDeemp dependent on the selected time 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 τDeemp...3 (3.7) x τDeemp. 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. The highcut function can be switched off by I2C-bus (bit D7, Highcut byte set to "0"). The setup of the highcut characteristics is described in 2.9. 3.5 PLL and Pilottone-Detector The PLL has the task to lock on the 19kHz pilottone during a stereo-transmission to allow a correct demodulation. The included pilottone-detector enables the demodulation if the pilottone reaches the selected pilottone threshold VPTHST. Two different thresholds are available. The detector output (signal STEREO, see Blockdiagram) can be checked by reading the status byte of the A679 via I2C-bus. During a Softmute the PLL can be set into "Hold"-mode which freezes the PLL's state (bit D4, Softmute byte). After releasing the Softmute the PLL will again follow the input signal only by correcting the phase error. 3.6 Fieldstrength Control The fieldstrength input is used to control the highcut- and the stereoblend-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 3.3 and 4. 3.7 EVEL-Input and -Gain To suppress undesired high frequency modulation on the highcut- and stereoblend-control signal the LEVEL signal is lowpass filtered firstly. The filter is a combination of a 1.st-order RC-lowpass at 53kHz (working as antialiasing filter) and a 1.st-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 "Stereodecoder-Adjustment"-byte to simplify a possible adjustment during the production of the carradio. This signal controls directly the Highcut stage whereas the signal is filtered again (fc=100Hz) before the stereoblend stage (see fig. 32). 3.8 Stereoblend Control The stereoblend 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 figs.28, 29). To adjust the external LEVEL-voltage to the internal range two values must be defined: the LEVEL gain LG and VSBL (see fig. 29). At the point of full channel separation the 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. 32/56 TDA7412 Figure 26. Internal stereoblend characteristics The gain can be programmed through 4 bits in the "Stereodecoder-Adjustment"-byte. All necessary internal reference voltages like REF5V are derived from a bandgap circuit. Therefore they have a temperature coefficient near zero. Figure 27. Relation between internal and external LEVEL-voltages for setup of Stereoblend INTERNAL VOLTAGES INTERNAL VOLTAGES SETUP OF VST SETUP OF VMO LEVEL INTERN REF 5V LEVEL INTERN REF 5V 70% LEVEL VSBL VSBL VMO VST 20% t FIELDSTRENGHT VOLTAGE VMO D00AU1168 VST t FIELDSTRENGHT VOLTAGE 3.9 Highcut Control The highcut control set-up is similar to the stereoblend 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 fig. 30). Figure 28. Highcut characteristics LOWPASS TIME CONSTANT 3.7•τ'Deemp 3•τDeemp DEEMPHASIS SHIFT ON OFF τDeemp τ'Deemp VHCL D00AU1169 VHCH FIELDSTRENGHT 33/56 TDA7412 4.0 FUNCTIONAL DESCRIPTION OF THE NOISEBLANKER 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 stereodecoder is held at the actual voltage for a time between 22 and 38µs in FM (370 and 645µs in AM-mode). The blockdiagram of the noiseblanker is given in fig.31. Figure 29. Block diagram of the noiseblanker AM/FM AMIF RECTIFIER + 14-56KHz LPF (1st. order) MPX 140KHz HPF (1st. order) RECTIFIER RECT + 140KHz HPF (2nd. order) + MONOFLOP - FM: 22 to 40µs AM: 370 to 6400µs HOLDN VTH PEAK THRESHOLD GENERATOR INTEGRATOR DISCHARGE CONTROL MPOUT + ADDITIONAL THRESHOLD CONTROL 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 triggerstage a pulse former generates the "blanking"-pulse. 4.1 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 filtered) to generate a signal called PEAK. The DC-charge/discharge behaviour can be adjusted as well as the transient behaviour(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. 4.2 Noise Controlled Threshold Adjustment (NCT) There are mainly two independent possibilities for programming the trigger threshold: 1. the low threshold in 8 steps (bits D1 to D3 of the noiseblanker-byte I) 2. and the noise adjusted threshold in 4 steps (bits D4 and D5 of the noiseblanker-byte I, see fig. 19). The low threshold is activ 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 fig. 22). 4.3 Additional Threshold Control Mechanism 4.3.1 Automatic Threshold Control by the Stereoblend voltage Besides the noise controlled threshold adjustment there is an additional possibility for influencing the trigger threshold which depends on the stereoblend control. The point where the MPX signal starts to become noisy is fixed by the RF part. Therefore also the starting point 34/56 TDA7412 of the normal noise-controlled trigger adjustment is fixed (fig. 24). 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 stereoblend. This increase of the threshold is programmable in 3 steps or switched off. 4.3.2 Over Deviation Detector If the system is tuned to stations with a high deviation the noiseblanker can trigger on the higher frequencies of the modulation or distortion. To avoid this behavior, 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 D6 and D7 of the noiseblanker-byte I (bit combination '00' turns off the detector, see fig. 23). 4.3.3 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 A679 offers a linear as well as a threshold driven control. The linear influence of the Multipath-Level on the PEAK-signal (D7 of Multipath-Control-Byte) gives a discharge slewrate of 1V/ms1 . The second possibility is to activate the threshold driven discharge which switches on the 18kOhm discharge if the Multipath-Level is below 2.5V (D7 of noiseblanker-byte II-byte). 1 The slewrate is measured with RDischarge=infinite and VMPout=2.5V AM mode of the Noiseblanker The A679 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 lowpassfilter forms an envelope detector which drives the noiseblanker's input via a 120kHz 1.st 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. 35/56 TDA7412 5.0 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 Stereoblend (see blockdiagram, fig. 32). 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 stereodecoder. This application is given in fig. 32. 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 30. Blockdiagram of the Multipath-Detector VDD = High-Cut-Infl. Attach<500µs Decay=2/10ms to HCC INT. INFLUENCE LOWPASS 100Hz LEVEL LOWPASS 53KHz to SB LOWPASS 2.2KHz VDD = SHIFT 0 ... 1.5V CHARGE 0.25µA/0.5µA VDD INT. INFLUENCE = 300µA Stereoblend-Infl. FAST CHARGE Attach=1ms Decay=4/8s MP HOLD MP_OUT MP_IN BANDPASS 19KHz RECTIFIER GAIN 2 bits GAIN 2 bits 470nF D00AU1166 6.0 QUALITY DETECTOR The A679 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 : VQual = 1.6 (VNoise-0.8 V)+ a (REF5V-VMpout). The noise-signal is the PEAK-signal without additional influences (see 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. 7.0 TESTMODE During the Testmode, which can be activated by setting bit D0 and bit D1 of the stereodecoder 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. 36/56 TDA7412 8.0 DUAL MPX USAGE 8.1 Feature Description The A679 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 1 (Please note that the thresholds have a hysteresis of 500mV). In this mode the stereodecoder highohmic-mute mutes both inputs in parallel. Figure 31. MPX/ MPX1 1 100K 40K INGAIN 3.5...11dB step 2.5dB 40K MD2G/ MPX2 1 100K MD2/ CONTROL 1 CONTROL CIRCUITRY D00AU1167 8.2 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 fig. 33). 37/56 TDA7412 9.0 I²C BUS INTERFACE 9.1 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 MSB 1 S 0 SUBADDRESS LSB 0 0 1 1 MSB 0 R/W ACK C AZ DATA 1....DATA n LSB I A A A A A MSB ACK LSB DATA 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 9.2 Auto increment If bit I in the subaddress byte is set to "1", the autoincrement of the subaddress is enabled. 9.3 TRANSMITTED DATA (send mode) MSB X LSB 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. 9.4 Reset Condition 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 : MSB 1 LSB 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 VREF (VOUT= VDD/2). 38/56 TDA7412 9.5 SUBADDRESS (receive mode) MSB LSB FUNCTION I2 I1 I0 A4 A3 A2 A1 A0 Compander Hold off on 0 1 AutoZero Remain off on 0 1 Auto-Increment Mode off on 0 1 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 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 Subaddress Main Source Selector Main Loudness Volume Treble Bass Mixing Programming SoftMute Voice-Band Second Source Selector Second Source Loudness Subwoofer-Config. / Bass SoftStep Time 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 Stereodecoder Noise-Blanker I Noise-Blanker II AM / AM-Noiseblanker High-Cut Control Fieldstr. & Quality Multipath-Detector Stereodecoder Adjustment Configuration Stereodecoder Testing Sterodecoder 39/56 TDA7412 9.6 DATA BYTE SPECIFICATION The status after Power-On-Reset is marked bold-face / underlined in the programming tables. 9.6.1 Main Selector (0) MSB LSB FUNCTION D7 D6 0 0 : 1 1 D5 0 0 : 1 1 D4 0 0 : 1 1 D3 D2 D1 D0 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 Source Selector FD1 / SE2 SE3 FD2 SE1 MD2 MD1 / SE4 Stereodecoder AM Input Gain 0dB 1dB : 14dB 15dB 0 1 : 0 1 Mute off on 0 1 9.6.2 Main Loudness (1) MSB LSB FUNCTION D7 D6 0 0 1 1 0 1 40/56 D5 0 1 0 1 D4 D3 D2 D1 D0 0 0 : 0 0 : 1 : 0 0 : 1 1 : 0 : 0 0 : 1 1 : 0 : 0 0 : 1 1 : 1 : 0 1 : 0 1 : 1 : Attenuation 0 dB -1 dB : -14 dB -15 dB : -19 dB not allowed Center Frequency 200Hz 400Hz 600Hz 800Hz Loudness Order First Order Second Order TDA7412 9.6.3 Volume (2) MSB LSB ATTENUATION D7 D6 D5 D4 D3 D2 D1 D0 0 0 : 0 0 0 : 0 0 0 : 1 1 0 0 : 0 0 0 : 0 1 1 : 1 1 0 0 : 0 0 0 : 1 0 0 : 0 0 0 0 : 1 1 1 : 1 0 0 : 1 1 0 0 : 1 1 1 : 1 0 0 : 1 1 0 0 : 0 0 0 : 1 0 0 : 1 1 0 0 : 0 0 1 : 1 0 0 : 1 1 0 1 : 0 1 0 : 1 0 1 : 0 1 Gain/Attenuation (+32.0dB) (+31.5dB) : +20 .0dB +19.5dB +19.0dB : +0.5dB 0.0dB -0.5dB : -79.0dB -79.5dB Note: It is not recommended to use a gain more than 20dB for system performance reason. In general, the max. gain should be limited by software to the maximum value, which is needed for the system. 9.6.4 Treble Filter (3) MSB LSB FUNCTION D7 D6 0 0 1 1 0 1 D5 0 1 0 1 D4 D3 D2 D1 D0 0 0 : 0 0 1 1 : 1 1 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 1 : 0 1 1 0 : 1 0 Treble Steps -15dB -14dB : -1 dB 0 dB 0 dB +1 dB : +14 dB +15dB Treble Center-frequency 10.0 kHz 12.5 kHz 15.0 kHz 17.5 kHz Subwoofer+Center-Speaker Mode On Off 41/56 TDA7412 9.6.5 Bass Filter (4) MSB LSB FUNCTION D7 D6 0 0 1 1 D5 D4 D3 D2 D1 D0 0 0 : 0 0 1 1 : 1 1 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 1 : 0 1 1 0 : 1 0 Bass Steps -15dB -14dB : -1 dB 0 dB 0 dB +1 dB : +14 dB +15dB Bass Q-Factor 1.0 1.25 1.5 2.0 0 1 0 1 Bass DC-Mode Off On 0 1 9.6.6 Mixing Programming (5) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 0 0 1 1 0 1 0 1 0 1 0 1 0 1 42/56 0 1 0 1 Mixing Mute enable Mixing Source Beep MD1 MD2 FM mono Mixing Target Speaker LF off Speaker LF on Speaker RF off Speaker RF on Speaker LR off Speaker LR on Speaker RR off Speaker RR on Stereo Subw. using internal Highpass-Filter On Off TDA7412 9.6.7 Soft Mute (6) MSB D7 LSB D6 D5 D4 D3 D2 D1 0 1 0 0 1 1 0 1 0 1 SoftMute On (Mute) Off Mutetime = 0.48ms Mutetime = 0.96ms Mutetime = 123ms Mutetime = 324 ms Influence on Stereodecoder Highohmic-Mute on off 0 1 Influence on Pilot-detector Hold and MP-Hold on off 0 1 Influence on SoftMute on off 0 1 0 0 1 1 FUNCTION D0 Beep Frequencies 600 Hz 780 Hz 1.56 kHz 2.4 kHz 0 1 0 1 9.6.8 VoiceBand (7) MSB D7 LSB D6 D5 D4 D3 D2 D1 0 1 0 1 0 1 0 0 0 1 1 1 1 1 0 1 0 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 FUNCTION D0 Voice-Band Low-Pass Enable Filter off Filter on Voice-Band Low-Pass Frequency 3 kHz 6 kHz Voice-Band High-Pass Enable Filter off Filter on High-Pass Cut-Off-Frequency 90Hz 135Hz 180Hz 215Hz 300Hz 450Hz 600Hz 750Hz Anti-Clipping Enable on off Anti-Clipping Input MP-In AM 43/56 TDA7412 9.6.9 Second Source Selector (8) MSB LSB FUNCTION D7 D6 0 0 : 1 1 D5 0 0 : 1 1 D4 0 0 : 1 1 D3 D2 D1 D0 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 Source Selector FD1 / SE2 SE3 FD2 SE1 MD2 MD1 / SE4 Stereodecoder AM Input Gain 0dB 1dB : 14dB 15dB 0 1 : 0 1 Mute off on 0 1 9.6.10Second Loudness (9) MSB LSB FUNCTION D7 D6 0 0 1 1 0 1 44/56 D5 0 1 0 1 D4 D3 D2 D1 D0 0 0 : 0 0 : 1 : 0 0 : 1 1 : 0 : 0 0 : 1 1 : 0 : 0 0 : 1 1 : 1 : 0 1 : 0 1 : 1 : Attenuation 0 dB -1 dB : -14 dB -15 dB : -19 dB not allowed Center Frequency 200Hz 400Hz 600Hz 800Hz Loudness Order First Order Second Order TDA7412 9.6.11Subwoofer Configuration / Bass (10) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 0 1 1 0 1 0 1 Subwoofer Outputs differential (mono) single ended (stereo) 0 1 Subwoofer Source Second Source Main Source 0 1 Subwoofer Phase 180° 0° 0 1 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 Subwoofer Filter off 80Hz 120Hz 160Hz Bass Center-Frequency 60Hz 80Hz 70Hz 90Hz 100Hz 130Hz 150Hz 200Hz 0 1 0 1 0 1 0 1 9.6.12Soft Step Time (11) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 0 Not used Not used Not used 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 1 0 1 SoftStep-Time 160µs 1.28ms 5.12ms 20.4ms Not used 45/56 TDA7412 9.6.13Configuration Audioprocessor I (12) MSB D7 LSB D6 D5 D4 D3 D2 D1 SoftStep (Volume & Speaker Attenuator0 off on 0 1 Main Loudness flat Filter ON 0 1 Second Loudness flat Filter ON 0 1 0 0 1 1 0 0 1 1 FUNCTION D0 Front Speaker not allowed Second Source internal coupled Main Source AC-coupled Main Source internal coupled 0 1 0 1 Rear Speaker not allowed Second Source internal coupled Main Source AC-coupled Main Source internal coupled 0 1 0 1 9.6.14Configuration Audioprocessor II (13) MSB D7 LSB D6 D5 D4 D3 D2 D1 0 1 0 0 1 1 0 1 0 0 1 1 0 1 0 1 46/56 0 1 0 1 0 1 0 1 FUNCTION D0 Pause Detector off on Pause ZC Window 160mV 80mV 40mV not allowed FD1 Mode single ended differential FD1 Attenuation -12dB -6dB -6dB 0dB FD2 Attenuation -6dB 0dB MD1 Mode single ended differential TDA7412 9.6.15Speaker, Subwoofer and Mixer Level-Control (14-20) The programming of all Speaker-, Subwoofer and Mixing Level-Controls are the same. MSB LSB ATTENUATION D7 D6 D5 D4 D3 D2 D1 D0 1 : 1 1 0 0 : 0 0 : 0 0 0 : 0 0 0 0 : 0 0 : 1 1 0 : 0 0 0 0 : 0 0 : 0 0 0 : 0 0 0 0 : 0 1 : 0 0 1 : 0 0 0 0 : 1 0 : 1 1 1 : 0 0 0 0 : 1 0 : 1 1 1 : 0 0 0 0 : 1 0 : 1 1 1 : 1 0 0 1 : 1 0 : 0 1 +15 dB : +1 dB 0 dB 0 dB -1 dB : -15 dB -16 dB : -78 dB -79 dB x 1 1 x x x x x Mute 9.6.16Testing Audioprocessor (21) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 0 0 0 0 1 1 1 1 0 0 1 0 1 0 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 Audioprocessor Testmode off on Test-Multiplexer not allowed not allowed not allowed 200kHz Oscillator not allowed not allowed NB-Hold internal Reference Not used Clock external internal AZ Function off on SC-Clock Fast Mode Normal Mode Note : This byte is used for testing or evaluation purposes only and must not set to other values than "11101110" in the application! 47/56 TDA7412 9.6.17Stereodecoder (22) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 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 1 Input AM-Pin Input MPX-Pin 0 1 Forced MONO MONO/STEREO switch automatically 0 1 0 0 0 1 1 0 1 1 STD Unmuted STD Muted Pilot Threshold HIGH Pilot Threshold LOW Deemphasis 50µs (37.5µs1) Deemphasis 62.5µs (46.9µs1) Deemphasis 75µs (56.3µs1) Deemphasis 100µs (75µs1) Notes: 1. If Deemphasis-Shift enabled (Subaddr.26/Bit7 = 0) 9.6.18Noiseblanker I (23) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 48/56 0 1 0 1 0 1 0 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 Noiseblanker off Noiseblanker on Low Threshold 65mV Low Threshold 60mV Low Threshold 55mV Low Threshold 50mV Low Threshold 45mV Low Threshold 40mV Low Threshold 35mV Low Threshold 30mV Noise Noise Noise Noise Controlled Controlled Controlled Controlled Threshold Threshold Threshold Threshold 320mV 260mV 200mV 140mV Overdeviation Adjust 2.8V Overdeviation Adjust 2.0V Overdeviation Adjust 1.2V Overdeviation Detector OFF TDA7412 9.6.19Noiseblanker II (24) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 0 0 1 1 0 0 1 1 0 0 1 1 PEAK charge current low high Fieldstrength adjust 2.3V 1.8V 1.3V OFF 0 1 0 1 Blank Time FM / AM 38µs / 1.2ms 25.5µs / 800µs 32µs / 1.0s 22µs / 640µs 0 1 0 1 Noise Rectifier Discharge Resistor R = infinite RDC = 56k RDC = 33k RDC = 18k 0 1 0 1 Strong Multipath influence on PEAK 18k off on (18k discharge if VMPout< 2.5V) 0 1 9.6.20AM / FM-Noiseblanker (25) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 0 0 0 0 1 1 1 1 0 0 1 1 1 1 0 1 0 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 Stereodecoder Mode FM AM AM Rectifier Gain 6dB 8dB 10dB 12dB 14dB 16dB 18dB 20dB Rectifier Cut-Off Frequency 14.0kHz 18.5kHz 28.0kHz 56.0kHz must be "1" 49/56 TDA7412 9.6.21High-Cut (26) MSB D7 LSB D6 D5 D4 D3 D2 D1 0 1 0 0 1 1 0 0 1 1 0 0 1 1 FUNCTION D0 High-Cut off on max. High-Cut 2dB 5dB 7dB 10dB 0 1 0 1 VHCH to be at 42% REF5V 50% REF5V 58% REF5V 66% REF5V 0 1 0 1 VHCL to be at 16.7% VHCH 22.2% VHCH 27.8% VHCH 33.3% VHCH 0 1 0 1 Deemphasis Shift On Off 0 1 9.6.22Fieldstrength Control (27) MSB D7 LSB D6 D5 0 0 1 1 0 0 1 1 50/56 0 1 0 1 D4 0 1 0 1 D3 D2 D1 D0 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 FUNCTION 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% REF5V 66.6% REF5V 70.0% REF5V Quality Detector Coefficient a=0.7 a=0.85 a=1.0 a=1.15 HCC-Level-Shift (only Level through MPD) 0.0V 500mV 1.0 V 1.5 V TDA7412 9.6.23Multipath Detector (28) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 0 0 1 1 0 0 1 1 Fast Load on off Bandpass Gain 6dB 12dB 16dB 18dB 0 1 0 1 Rectifier Gain Gain = 7.6dB Gain = 4.6dB Gain = 0dB disabled 0 1 0 1 Charge Current at MP-Out 0.25µA 0.50µA 0 1 Multipath on High-Cut Decay-Time 2ms 10ms 0 1 Multipath influence on PEAK Discharge off -1V/ms 0 1 9.6.24Stereodecoder Adjustment (29) MSB LSB FUNCTION D2 D1 D0 0 0 0 : 0 : 0 0 0 0 : 1 : 1 0 0 1 : 0 : 1 0 1 0 : 0 : 1 Roll-Off Compensation not allowed 7.2% 9.4% : 13.7% : 20.2% 1 1 1 : 1 : 1 0 0 0 : 1 : 1 0 0 1 : 0 : 1 0 1 0 : 0 : 1 not allowed 19.6% 21.5% : 25.3% : 31.0% D7 D6 0 0 0 : 1 D5 0 0 0 : 1 D4 0 0 1 : 1 D3 0 1 0 : 1 LEVEL Gain 0dB 0.4dB 0.8dB : 6dB 51/56 TDA7412 9.6.25Stereodecoder Configuration (30) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 Multipath Influence on Stereo-Blend On Off 0 1 0 1 1 1 1 1 1 x Multipath Influence on High-Cut On Off 1 x Level-Input over Multipath-Detector1 On Off 0 1 Dual MPX Mode On Off 1 must be "1" Notes: 1. Using the Multipath Time-Constants for Stereo-Bland and High-Cut 9.6.26Testing Stereodecoder(31) MSB LSB FUNCTION D7 D6 D5 D4 D3 D2 D1 D0 0 1 0 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 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 Main Testmode off on Stereodecoder Testmode off on Testsignals F228 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 Off On 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! 52/56 TDA7412 10.0 APPLICATION INFORMATION Figure 32. Application Diagram (standard configuration) OUTLR OUTLF 220nF SEL 220nF SER 220nF FD1L+ 220nF FD1L220nF FD1R+ 220nF FD1R220nF FD2L+ 220nF FD2L220nF FD2R+ 220nF FD2R220nF AM 220nF MPX1 470nF OUTLF SEL SER FD1L+ FD1L- FD1R+ FD1R- FD2L+ FD2L- FD2R+ FD2R- AM MPX MPOUT OUTLR 1 OUTRF OUTRR 28 29 30 OUTRR OUTRF OUTSWL OUTSWL 27 OUTSWR OUTSWR 26 OUTSSL OUTSSL 25 24 23 44 2 43 3 42 4 41 5 6 40 7 39 38 8 37 9 36 10 35 11 34 13 33 32 16 31 12 AMIF 14 LEVEL 15 MPIN 17 QUAL 19 18 SM GND 20 SDA OUTSSR 220nF MD2G MD2G 220nF MD2 MD2 220nF MD1G MD1G 220nF MD1 MD1 MUX PAUSE 47nF MUX 10µF CREF ACOUTL ACOUTL ACOUTR SWINR SWINL ACINLF ACOUTR 220nF 220nF 470nF 470nF ACINLR ACINRF ACINRR 22 21 SCL OUTSSR VDD + VB1 = 220nF 100nF - 9 AMIF LEVEL MPIN QUAL SMUTE SDA SCL D00AU1161 53/56 TDA7412 Figure 33. Application Diagram (Dual MPX mode) OUTRF OUTLF 100nF SEL 100nF SER 220nF FD1L+ 220nF FD1L220nF FD1R+ 220nF FD1R220nF FD2L+ 220nF FD2L220nF FD2R+ 220nF FD2R100nF AM 100nF MPX1 470nF OUTLF SEL SER FD1L+ FD1L- FD1R+ FD1R- FD2L+ FD2L- FD2R+ FD2R- AM MPX MPOUT OUTLR 1 OUTRF OUTRR 28 29 30 OUTRR OUTLR OUTSWL OUTSWL 27 OUTSWR OUTSWR 26 OUTSSL OUTSSL 25 24 23 2 44 43 3 42 4 41 OUTSSR MPX2 MD2 40 39 7 38 8 37 9 36 10 35 11 34 13 33 32 16 31 12 AMIF 14 LEVEL 15 MPIN 17 QUAL 19 18 SM GND 20 MD1G 220nF MD1 MD1 SDA SCL MUX 10µF CREF ACOUTL ACOUTL ACOUTR SWINR SWINL ACINLF ACOUTR 220nF 220nF 470nF ACINLR ACINRF ACINRR VDD + VB1 = 100nF - 9 AMIF 54/56 LEVEL MPIN QUAL SMUTE SDA SCL MUX PAUSE 47nF 22 21 VPX CONTROL 220nF MD1G 5 6 OUTSSR 100nF MD2G D00AU1158 470nF TDA7412 mm inch DIM. MIN. TYP. A MAX. MIN. TYP. 1.60 A1 0.05 A2 1.35 B 0.30 C 0.09 D 11.80 D1 9.80 D3 0.063 0.15 0.002 1.40 1.45 0.053 0.055 0.057 0.37 0.45 0.012 0.015 0.018 0.20 0.004 12.00 12.20 0.464 0.472 0.480 10.00 10.20 0.386 0.394 0.401 8.00 0.006 0.008 0.315 E 11.80 12.00 12.20 0.464 0.472 0.480 E1 9.80 10.00 10.20 0.386 0.394 0.401 E3 8.00 0.315 e 0.80 0.031 L 0.45 0.60 L1 0.75 0.018 1.00 k OUTLINE AND MECHANICAL DATA MAX. 0.024 0.030 TQFP44 (10 x 10 x 1.4mm) 0.039 0˚(min.), 3.5˚(typ.), 7˚(max.) D D1 A A2 A1 33 23 34 22 0.10mm .004 B E B E1 Seating Plane 12 44 11 1 C L e K TQFP4410 0076922 D 55/56 TDA7412 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners © 2003 STMicroelectronics - All rights reserved STMicroelectronics GROUP OF COMPANIES Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States www.st.com 56/56