STMICROELECTRONICS TDA7402

TDA7402
CARRADIO SIGNAL PROCESSOR
PRODUCT PREVIEW
■
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: TDA7402
DESCRIPTION
Stereodecoder:
■ RDS MUTE
■
NO EXTERNAL ADJUSTMENTS
■
AM/FM NOISEBLANKER WITH SEVERAL
TRIGGER CONTROLS
■
PROGRAMMABLE MULTIPATH DETECTOR
■
QUALITY DETECTOR OUTPUT
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.
March 2000
This is preliminary information on a new product now in development. Details are subject to change without notice.
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TDA7402
PIN CONNECTION (Top view)
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
R th j-pins
Parameter
Thermal Resistance Junction-pins max
SUPPLY
Symbol
Parameter
Test Conditio n
Min.
Typ.
Max.
Unit
7.5
9
10
V
VS
Supply Voltage
IS
Supply Current
V S = 9V
50
mA
Ripple Rejection @ 1kHz
Audioprocessor (all Filters flat)
60
dB
Stereodecoder + Audioprocessor
55
dB
SVRR
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TDA7402
BLOCK DIAGRAM
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TDA7402
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
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programmable threshold
TDA7402
ELECTRICAL CHARACTERISTICS
VS = 9V; Tamb = 25°C; RL = 10kΩ; all gains = 0dB; f = 1kHz; unless otherwise specified
Symbol
Parameter
Test Conditio n
Min.
Typ.
Max.
Unit
70
100
130
kΩ
INPUT SELECTOR
Rin
Input Resistance
VCL
Clipping Level
2.2
2.6
VRMS
SIN
Input Separation
80
100
dB
GIN MIN
Min. Input Gain
-1
0
GIN MAX
Max. Input Gain
15
dB
GSTEP
Step Resolution
1
dB
Adjacent Gain Steps
1
mV
GMIN to GMAX
6
mV
0.5
mV
VDC
Voffset
DC Steps
all single ended Inputs
Remaining offset with AutoZero
+1
dB
DIFFERENTIAL STEREO INPUTS
Rin
G CD
CMRR
e NO
Input Resistance
(see Figure 1)
Differential
Gain
only at true differential input
Common Mode Rejection Ratio
70
100
130
kΩ
0
dB
-6
dB
-12
dB
V CM = 1VRMS @ 1kHz
46
70
dB
V CM = 1VRMS @ 10kHz
46
60
dB
9
µV
Output-Noise @ Speaker-Outputs 20Hz - 20kHz, flat; all stages 0dB
DIFFERENTIAL MONO INPUTS
Rin
CMRR
Input Impedance
Differential
40
56
kΩ
Common Mode Rejection Ratio
V CM = 1VRMS @ 1kHz
40
70
dB
V CM = 1VRMS @ 10kHz
40
60
dB
BEEP CONTROL
VRMS
Beep Level
Mix-Gain = 6dB
350
mV
fBeep
Beep Frequency
fBeep1
600
Hz
fBeep2
780
Hz
fBeep1
1.56
kHz
fBeep1
2.4
kHz
-6/-6
dB
MIXING CONTROL
MLEVEL
Mixing Ratio
Main / Mix-Source
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TDA7402
ELECTRICAL CHARACTERISTICS (continued)
Symbol
Parameter
Test Conditio n
Min.
Typ.
Max.
Unit
GMAX
Max. Gain
15
dB
AMAX
Max. Attenuation
-79
dB
A STEP
Attennuation Step
1
dB
225
Ω
MULTIPLEXER OUTPUT 1
ROUT
Output Impedance
RL
Output Load Resistance
CL
Output Load Capacitance
VDC
2
kΩ
10
DC Voltage Level
nF
4.5
V
LOUDNESS CONTROL
A STEP
Step Resolution
1
dB
AMAX
Max. Attenuation
19
dB
fPeak
Peak Frequency
fP1
200
Hz
fP2
400
Hz
fP3
600
Hz
fP4
800
Hz
VOLUME CONTROL
GMAX
Max. Gain
15.5
dB
AMAX
Max. Attenuation
79.5
dB
A STEP
Step Resolution
0.5
dB
EA
ET
VDC
Attenuation Set Error
G = -20 to +20dB
-0.75
0
+0.75
dB
G = -80 to -20dB
-4
0
3
dB
2
dB
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
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Mute Attenuation
Delay Time
Low Threshold for SM-Pin2
80
100
dB
T1
0.48
ms
T2
0.96
ms
T3
123
ms
T4
324
ms
1
V
TDA7402
ELECTRICAL CHARACTERISTICS (continued)
Symbol
VTH high
Parameter
Test Conditio n
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
kΩ
3.3
V
Notes: 1. If configured as Multiplexer-Output
2. The SM-Pin is active low (Mute = 0)
BASS CONTROL
CRANGE
Control Range
+15
dB
A STEP
Step Resolution
1
dB
fC1
60
Hz
fC2
70
Hz
fC3
80
Hz
fC4
90
Hz
fC5
100
Hz
fC6
130
Hz
fC7
150
Hz
fC8
200
Hz
Q1
1
Q2
1.25
Q3
1.5
Q4
2
DC = off
0
dB
DC = on
4.4
dB
fC
Q BASS
DCGAIN
Center Frequency
Quality Factor
Bass-DC-Gain
TREBLE CONTROL
CRANGE
Control Range
+15
dB
A STEP
Step Resolution
1
dB
fC1
10
kHz
fC2
12.5
kHz
fC3
15
kHz
fC4
17.5
kHz
fC
Center Frequency
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TDA7402
ELECTRICAL CHARACTERISTICS (continued)
Symbol
Parameter
Test Conditio n
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
15
dB
AMAX
Max. Attenuation
79
dB
A STEP
Step Resolution
1
dB
AMUTE
Output Mute Attenuation
90
dB
EE
VDC
80
Attenuation Set Error
DC Steps
Adjacent Attenuation Steps
0.1
2
dB
5
mV
Notes: 1. If configured as Pause-Output
AUDIO OUTPUTS
VCLIP
Clipping Level
RL
Output Load Resistance
CL
Output Load Capacitance
d = 0.3%
2.2
2.6
VRMS
2
kΩ
10
nF
120
W
ROUT
Output Impedance
30
VDC
DC Voltage Level
4.5
V
fHP1
90
Hz
fHP2
135
Hz
fHP3
180
Hz
fHP4
215
Hz
fHP5
300
Hz
fHP6
450
Hz
fHP7
600
Hz
fHP8
750
Hz
VOICE BANDPASS
fHP
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Highpass corner frequency
TDA7402
ELECTRICAL CHARACTERISTICS (continued)
Symbol
fLP
Parameter
Lowpass corner frequency
Test Conditio n
Min.
Typ.
Max.
Unit
fLP1
3
kHz
fLP2
6
kHz
SUBWOOFER ATTENUATORS
Rin
Input Impedance
35
50
65
kΩ
GMAX
Max. Gain
15
dB
AATTN
Max. Attenuation
79
dB
A STEP
Step Resolution
1
dB
AMUTE
Output Mute Attenuation
90
dB
EE
VDC
80
Attenuation Set Error
DC Steps
2
dB
5
mV
Adjacent Attenuation Steps
1
fLP1
80
Hz
fLP2
120
Hz
fLP3
160
Hz
SUBWOOFER Lowpass
fLP
Lowpass corner frequency
Notes: 1. If programmed as Subwoofer Diff.-Output
DIFFERENTIAL OUTPUTS1)
RL
RDL
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
CLMAX
Capacitive load at each output
C Lmax at each Output to Ground
10
nF
CDLMAX
Capacitive load differential
C Lmax between Output terminals
5
nF
VOffset
DC Offset at pins
Output muted
10
mV
ROUT
Output Impedance
30
Ω
VDC
DC Voltage Level
4.5
V
eNO
Output Noise
Output muted
6
µV
Vi < -46dB
19
dB
Vi < -46dB, Anti-Clip=On
29
dB
-10
COMPANDER
GMAX
max. Compander Gain
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TDA7402
ELECTRICAL CHARACTERISTICS (continued)
Symbol
tAtt
tRel
VREF
CF
Parameter
Attack time
Release time
Compander Reference InputLevel (equals 0dB)
Compression Factor
Test Conditio n
Min.
Typ.
Max.
Unit
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
V REF1
0.5
VRMS
V REF2
1.0
VRMS
V REF3
2.0
VRMS
Output Signal / Input Signal
0.5
Notes: 1. If programmed as Subwoofer Diff.-Output
GENERAL
e NO
S/N
d
Output Noise
Signal to Noise Ratio
distortion
SC
Channel Separation left/right
ET
Total Tracking Error
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BW = 20Hz - 20kHz
output muted
all gains = 0dB single ended inputs
3
10
µV
µV
all gains = 0dB
flat; VO = 2VRMS
106
dB
bass, treble at +12dB;
a-weighted; VO = 2.6VRMS
100
dB
V IN = 1VRMS ; all stages 0dB
0.005
%
VOUT = 1VRMS ; Bass & Treble =
12dB
0.05
%
100
dB
AV = 0 to -20dB
0
1
dB
AV = -20 to -60dB
0
2
dB
TDA7402
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
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.
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TDA7402
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 A619 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).
12/59
TDA7402
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
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TDA7402
1.4.3 Loudness Order
Different shapes of 1st and 2nd-Order Loudness
Figure 4. 1st and 2nd Order Loudness @ Attn. = 15dB, Pf =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
Note: Please notice that a started Mute-action is always terminated and could not be interrupted by a change of the mute -signal .
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TDA7402
1.6 SoftStep-Volume
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
1dB
0.5dB
SS Time
-0.5dB
-1dB
Note: For steps more than 0.5dB 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
10 0.0
Hz
1.0K
10 .0K
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TDA7402
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, C
f = 80Hz
15.0
12.5
10.0
7.5
5.0
2.5
0.0
10.0
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100.0
1.0K
10.0K
TDA7402
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, C
f = 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
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TDA7402
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.
18/59
TDA7402
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
Hz
1.0K
10.0K
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TDA7402
1.11 Compander
Signal-Compression
A fully integrated signal-compressor with programmable Attack- and Decay-times is present in the A619 (see
Figure 15).
The compander consists of a signal-level detection, an A/D-Converter plus adder and the normal SoftStep-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 IIC-Bus. Assuming reference-level or higher at the compander input, the output of the
ADC is 0. At lower levels the voltage is increasing with 1Bit/dB. It is obvious that with this configuration and a
0.5dB-step volume-stage the compression rate is fixed to 2:1 (1dB less at the input leads to 0.5dB less at the
output).
The internal reference-level of the compander is programmable in three steps from 0.5VRMS 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 InGainstage 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.
Figure 15. Compander Block Diagram
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 volume with
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TDA7402
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.
1.11.1Characteristic
To achieve the desired compression characteristic like shown below the volume has to be decreased by 4dB.
Figure 16. Compander Characteristic
1.11.2I C -BUS-Timing
0
-8dB
-10
2:1
Output Level
-20
-38dB
dB
-30
15dB
-40
-50
-60
0
-10
-20
-30
-40
Input Level
-50
-60
During the Compander is working a volumeword coming from this stage is added to the
I2C-Bus volume-word and the volume is
changed with a soft slope between adjacent
steps (SoftStep-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 companderON is the following:
dB
1. Set the compander-hold-bit
2. Wait the actual SoftStep-time
3. Change the volume
4. Reset the compander-hold-bit
The SoftStep-times are in compander-ON condition automatically adapted to the attack-time of the Compander.
In the following table the related SoftStep-times are shown:
Attack-Time
SoftStep-Time
6ms
0.16ms
12ms
0.32ms
24ms
0.64ms
48ms
1.28ms
1.12 AC-Coupling
In some applications additional signal manipulations are desired, for example surround-sound or more-bandequalizing. For this purpose an AC-Coupling is placed before the speaker-attenuators, which can be activated
or internally shorted by I C-Bus. In short condition the input-signal of the speaker-attenuator is available at the
AC-Outputs. The input-impedance of this AC-Inputs is 50kΩ .
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1.13 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 IIC-Bus programming. In figure 18 to 20 three examples are given.
Figure 17. Output Selector
1.14 Subwoofer
Several different applications are possible with the Subwoofer-circuit:
1. Subwoofer-Filter OFF
a. Main-source stereo (AC-coupled)
b. Second-source stereo (DC-coupled)
c. Main-source mono-differential (DC-coupled)
d. Second-source mono-differential (DC-coupled)
2. Subwoofer-Filter ON
a. Main-source mono-differential (DC-coupled)
b. Second-source mono-differential (DC-coupled)
c. Center-Speaker-Mode (filtered mono signal at SWL, unfiltered mono signal at SWR)
In all applications the phase of the output-signal can be configured to be 0° or 180° . In the Center-SpeakerMode only at the filtered output the phase is changed.
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Figure 18. Application1 using internal Highpass- and mono Low-pass-Filter
Figure 19. Application2 using internal Highpass- and external stereo Low-pass-Filter
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Figure 20. Application3 using pure external Filtering (e.g. DSP)
1.15 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 21. Output Selector
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1.16 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
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 Conditio n
Input Gain = 3.5dB
Min.
Typ.
Max.
Unit
0.5
1.25
Vrms
Vin
MPX Input Level
Rin
Input Resistance
100
kΩ
Gmin
Min. Input Gain
3.5
dB
Gmax
Max. Input Gain
11
dB
Gstep
Step Resolution
2.5
dB
SVRR
Supply Voltage Ripple Rejection
60
dB
50
dB
V ripple = 100mV, f = 1kHz
a
Max. Channel Separation
THD
Total Harmonic Distortion
fin=1kHz, mono
S+ N
N
Signal plus Noise to Noise Ratio
A-weighted, S = 2Vrms
91
dB
0.02
0.3
%
MONO/STEREO-SWITCH
VPTHST1
Pilot Threshold Voltage
for Stereo, PTH = 1
15
mV
VPTHST0
Pilot Threshold Voltage
for Stereo, PTH = 0
25
mV
for Mono, PTH = 1
12
mV
VPTHMO1 Pilot Threshold Voltage
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2.2 ELECTRICAL CHARACTERISTICS (continued)
Symbol
Parameter
VPTHMO0 Pilot Threshold Voltage
Test Conditio n
Min.
for Mono, PTH = 0
Typ.
19
Max.
Unit
mV
PLL
∆f/f
Capture Range
0.5
%
DEEMPHASIS and HIGHCUT
τDeempFM Deemphasis Timeconstants FM
MFM
REF5V
50
µs
V LEVEL >> VHCH
62.5
µs
V LEVEL >> VHCH
75
µs
V LEVEL >> VHCH
100
µs
Highcut Timeconstant Multiplier FM V LEVEL << VHCL
τDeempAM Deemphasis Timeconstants AM
M AM
V LEVEL >> VHCH
3
V LEVEL >> VHCH
37.5
µs
V LEVEL >> VHCH
47
µs
V LEVEL >> VHCH
56
µs
V LEVEL >> VHCH
75
µs
Highcut Timeconstant Multiplier AM V LEVEL << VHCL
3.7
Internal Reference Voltage
5
V
Lmin
min. LEVEL Gain
0
dB
L maxs
max. LEVEL Gain
6
dB
L Gstep
LEVEL Gain Step Resolution
see section 2.7
0.4
dB
VSBL min Min. Voltage for Mono
see section 2.8
20
%REF5V
VSBLmax Max. Voltage for Mono
see section 2.8
70
%REF5V
VSBLstep Step Resolution
see section 2.8
3.3
%REF5V
VHCHmin Min. Voltage for NO Highcut
see section 2.9
42
%REF5V
VHCHmax Max. Voltage for NO Highcut
see section 2.9
66
%REF5V
VHCHstep Step Resolution
see section 2.9
8.4
%REF5V
VHCLmin Min. Voltage for FULL High cut
see section 2.9
17
%VHCH
VHCLmax Max. Voltage for FULL High cut
see section 2.9
33
%VHCH
VHCLstep Step Resolution
see section 2.9
4.2
%REF5V
Carrier and harmonic suppression at the output
α19
Pilot Signal f=19kHz
50
dB
α38
Subcarrier f=38kHz
75
dB
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2.2 ELECTRICAL CHARACTERISTICS (continued)
Symbol
Parameter
Test Conditio n
Min.
Typ.
Max.
Unit
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
2.3 NOTES TO THE CHARACTERISTICS
2.3.1 Intermodulation Suppression
V O ( s ignal ) ( at1kHz )
α2 = -------------------------------------------------------------- ;- f = ( 2 ⋅ 10k Hz ) – 19kH z
VO ( spurious )( at1kHz ) s
V O ( s ignal ) ( at 1kHz )
---------------------------------------------- -f
; = ( 3 ⋅ 13k H z) – 38k H z
α3 = ----------------VO ( spuri ous )( at1kHz ) s
measured with: 91% pilot signal; fm = 10kHz or 13kHz.
2.3.2 Traffic Radio (V.F.) Suppression
V O ( signal ) ( at1kHz )
α57 ( V.W.F) = ---------------------------------------------------------------------------------------V O ( s purious ) ( at1kHz ± 23k Hz)
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 )
VO ( s ignal )( at1kHz )
-f
; = ( 2 ⋅ 38kH z ) – 67kH z
α67 = --------------------------------------------------------------VO ( spuri ous ) ( at1kHz ) s
measured with: 81% mono signal; 9% pilot signal; fm=1kHz; 10%SCA - subcarrier ( fS = 67kHz, unmodulated ).
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2.3.4 ACI ( Adjacent Channel Interference )
VO ( s ignal )( at1kHz )
-f
α114 = --------------------------------------------------------------; = 110k Hz – ( 3 ⋅ 38kH z )
VO ( spurious ) ( at4kHz ) s
VO ( s ignal )( at1kHz )
-f
α190 = --------------------------------------------------------------; = 186k Hz – ( 5 ⋅ 38kH z )
VO ( spurious ) ( at4kHz ) s
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
■
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
V TR
VTRNOISE
V RECT
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Parameter
Trigger Threshold 1)
noise controlled
Trigger Threshold
Rectifier Voltage
Test Condition
meas.with
VPEAK=0.9V
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
0.9
V
VMPX=50mV, f=150kHz
1.7
V
VMPX=200mV, f=150kHz
3.5
V
meas.with
VPEAK=1.5V
TDA7402
2.4.2 ELECTRICAL CHARACTERISTICS (continued)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
VRECTDEV Deviation dependent
Rectifier Voltage
meas.with
VMPX=500mV
(75kHz dev.)
11
10
01
00
0.9
(off)
1.2
2.0
2.8
VOP
VOP
VOP
VOP
VRECTFS
Fieldstrength
controlled Rectifier
Voltage
meas.with
VMPX=0mV,
VLEVEL<< VSBL
(fully mono)
11
10
01
00
0.9
(off)
1.4
1.9
2.4
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
adjustment
Signal PEAK in
Testmode
00
01
10
11
0.3
0.8
1.3
2.0
V/ms
SR PEAK
Noise rectifier
charge
Signal PEAK in
Testmode
0
1
10
20
mV/µs
VADJMP
Noise rectifier adjustment
through
Multipath
Signal PEAK in
Testmode
00
01
10
11
0.3
0.5
0.7
0.9
V/ms
R AMIF
AM IF Input resistance
35
GAMIF,min min. gain AM IF
GAMIF,max
max. gain AM IF
GAMIF,step
step gain AM IF
fAMIF,min
min. fc AM IF
Signal AM-RECTIFIER in
Testmode
Signal AM-RECTIFIER in
Testmode
fAMIF,max max. fc AM IF
50
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.
V
in
V
op
DC
T im e
T
R
T
HIGH
T
F
29/59
TDA7402
Figure 22. Trigger Threshold vs. VPEAK
V TH
2 60m V (0 0)
2 20m V (0 1)
1 80m V (1 0)
1 40m V (1 1)
M IN . TR IG . THR ES H OL D
NO IS E C ON TR OL LE D T RIG . TH RE S HO LD
6 5m V
8 S TE PS
3 0m V
0 .9 V
V
1.5 V
PEAK [V]
Figure 23. Fig. 23: Deviation Controlled Trigger Adjustment
VP E A K
[V
OP
]
00
2 .8
01
2 .0
10
1 .2
0 .9
D e te c to r o ff (11 )
20
32 .5
45
D E V IA T ION [KH z]
75
Figure 24. Fieldstrength Controlled Trigger Adjustment
VP E A K
MONO
S TERE O
≈ 3V
2 .4 V ( 0 0 )
1 .9 V (0 1 )
1 .4 V (1 0 )
N O IS E
0 .9 V
A T C _ S B O F F (1 1)
n o i sy s ig n a l
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TDA7402
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
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TDA7402
3.0 FUNCTIONAL DESCRIPTION OF STEREODECODER
Figure 25. Block diagram of Stereodecoder
The stereodecoder-part of the A619 (see Fig. 25) 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 A619 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.
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TDA7402
Figure 26. Signals during stereodecoder’s SoftMute
Figure 27. Signal-Control via SoftMute-Pin
3.2 InGain + Infilter
The InGain stage allows to adjust the MPX-signal to a magnitude of about 1Vrms 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 A619 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 A619 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
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TDA7402
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 A619 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.
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TDA7402
Figure 28. 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 29. Relation between internal and external LEVEL-voltages for setup of Stereoblend
70
20
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 30. Highcut characteristics
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TDA7402
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 31. Block diagram of the noiseblanker
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
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TDA7402
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 A619 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 R
Discharge=infinite and VMPout=2.5V
AM mode of the Noiseblanker
The A619 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.
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TDA7402
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 32. Blockdiagram of the Multipath-Detector
6.0 QUALITY DETECTOR
The A619 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.
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TDA7402
8.0 DUAL MPX USAGE
8.1 Feature Description
The A619 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 33.
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. 35).
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TDA7402
9.0 I C 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
S
1
0
SUBADDRESS
LSB
0
0
1
1
0
MSB
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).
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TDA7402
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
Subadd ress
Main Source Selector
Main Loudness
Volume
Treble
Bass
Mixing Programming
SoftMute
Voice-Band
Second Source Selector
Second Source Loudness
Subwoofer-Config. / Bass
Compander
Configuration Audioprocessor I
Configuration Audioprocessor II
Subwoofer attenuator L
Subwoofer attenuator R
Speaker attenuator LF
Speaker attenuator RF
Speaker attenuator LR
Speaker attenuator RR
Mixing Level Control
Testing Audioprocessor
Stereodecoder
Noise-Blanker I
Noise-Blanker II
AM / AM-Noiseblanker
High-Cut Control
Fieldstr. & Quality
Multipath-Detector
Stereodecoder Adjustment
Configuration Stereodecoder
Testing Sterodecoder
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TDA7402
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
Inpu t 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
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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
Loud ness Order
First Order
Second Order
TDA7402
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
Subwoof er+Center-Speaker Mode
On
Off
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TDA7402
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
44/59
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
TDA7402
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
Influ ence on Stereodecoder Highoh mic-Mute
on
off
0
1
Influ ence on Pilot-detector Hold and MP-Hold
on
off
0
1
Influ ence 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
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TDA7402
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
Inpu t 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
46/59
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
TDA7402
9.6.11Subwoofer Configuration / Bass (10)
MSB
LSB
FUNCTION
D7
D6
D5
D4
D3
D2
0
1
0
1
0
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
D1
D0
0
0
1
1
0
1
0
1
Subwoofer Filter
off
80Hz
120Hz
160Hz
Subwoofer Outputs
differential (mono)
single ended (stereo)
Subwoofer Source
Second Source
Main Source
Subwoofer Phase
180°
0°
Bass Center-Frequency
60Hz
80Hz
70Hz
90Hz
100Hz
130Hz
150Hz
200Hz
47/59
TDA7402
9.6.12Compander (11)
MSB
LSB
FUNCTION
D7
D6
D5
D4
D3
0
0
1
1
0
0
1
1
0
0
0
0
1
1
1
1
0
1
0
1
0
1
0
1
0
1
D1
D0
0
0
1
1
0
1
0
1
Activity / Reference Level
off
0.5V RMS
1VRMS
2VRMS
Attack-Times
6ms
12ms
24ms
49ms
Release-Times
390ms
780ms
1.17s
1.56s
0
1
0
1
0
0
1
1
0
0
1
1
D2
0
1
0
1
SoftStep-Time1)
160µs
320µs
640µs
1.28ms
2.56ms
5.12ms
10.2ms
20.4ms
Compander max. Gain
29dB
19dB
Notes: 1. The SoftStep-Times are only programmable while the Compander is not used.
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TDA7402
9.6.13Configuration Audioprocessor I (12)
MSB
D7
LSB
D6
D5
D4
D3
D2
D1
0
1
Main Loudness
flat
Filter ON
0
1
Second Loudn ess
flat
Filter ON
0
1
0
0
1
1
Compander Source
Main Selector
Second Source Selector
SoftStep
off
on
0
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
0
1
0
1
0
1
0
1
FUNCTION
D0
Pause Detector
off
on
Pause ZC Wind ow
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
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TDA7402
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
1
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-Multip lexer
Compander Log-Amp. Output
Compander Low-Pass Output
Compander DAC Output
200kHz Oscillator
not allowed
not allowed
NB-Hold
internal Reference
Compander Testmode
off
on
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!
50/59
TDA7402
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
Deemphasis
Deemphasis
Deemphasis
50µs (37.5µs1)
62.5µs (46.9µs1)
75µs (56.3µs1)
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
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
Low
Low
Low
Low
Low
Low
Low
Threshold
Threshold
Threshold
Threshold
Threshold
Threshold
Threshold
Threshold
Noise
Noise
Noise
Noise
65mV
60mV
55mV
50mV
45mV
40mV
35mV
30mV
Controlled Threshold
Controlled Threshold
Controlled Threshold
Controlled Threshold
Overdeviation
Overdeviation
Overdeviation
Overdeviation
320mV
260mV
200mV
140mV
Adjust 2.8V
Adjust 2.0V
Adjust 1.2V
Detector OFF
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TDA7402
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
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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”
TDA7402
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
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
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TDA7402
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
D7
D6
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%
0
0
0
:
1
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D5
0
0
0
:
1
D4
0
0
1
:
1
D3
0
1
0
:
1
LEVEL Gain
0dB
0.4dB
0.8dB
:
6dB
TDA7402
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!
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TDA7402
10.0 APPLICATION INFORMATION
Figure 34. Application Diagram (standard configuration)
TDA7402
56/59
TDA7402
Figure 35. Application Diagram (Dual MPX mode)
TDA7402
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TDA7402
Figure 36.
mm
DIM.
MIN.
TYP.
A
inch
MAX.
MIN.
TYP.
1.60
A1
0.05
A2
1.35
B
0.30
C
0.09
0.063
0.006
0.15
0.002
1.40
1.45
0.053
0.055
0.057
0.37
0.45
0.012
0.014
0.018
0.20
0.004
0.008
D
12.00
0.472
D1
10.00
0.394
D3
8.00
0.315
e
0.80
0.031
E
12.00
0.472
E1
10.00
0.394
E3
8.00
0.315
L
0.45
0.60
0.75
OUTLINE AND
MECHANICAL DATA
MAX.
0.018
0.024
L1
1.00
K
0°(min.), 3.5°(typ.), 7°(max.)
0.030
0.039
TQFP44 (10 x 10)
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
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TDA7402
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to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
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