Features
■ Input multiplexer
– PD/SE4: pseudo differential stereo input,
programmable as single-ended input
– SE1: stereo single-end input
– SE2: stereo single-end input
– SE3: stereo single-end input
– Input gain adjust from 0 to 15dB with 1dB
steps
– Internal offset-cancellation (AutoZero)
■ Loudness
– Second order frequency response
– Programmable center frequency
(400 Hz / 800 Hz / 2400 Hz)
– 15dB with 1dB steps
– Selectable low and high frequency boost
– Selectable flat-mode (constant attenuation)
■ Volume
– +15dB to -79dB with 1dB step resolution
– Soft-step control with programmable blend
times
■ Bass
– Second order frequency response
– Center frequency programmable in 4 steps
(60 Hz / 80 Hz / 100 Hz / 200 Hz)
– Q programmable 1.0/1.25/1.5/2.0
– DC gain programmable
– -15 to 15dB range with 1dB resolution
■ Middle
– Second order frequency response
– Center frequency programmable in 4 steps
(500 Hz / 1 kHz / 1.5 kHz / 2.5 kHz)
Table 1. Device summary
TDA7418
3 band car audio processor
SO20
– Q programmable 0.5/0.75/1.0/1.25
– -15 to 15dB range with 1dB resolution
■ Treble
– Second order frequency response
– Center frequency programmable in 4 steps
(10 kHz / 12.5 kHz / 15 kHz / 17.5 kHz)
– -15 to 15dB range with 1dB resolution
■ Speaker
– 4 independent soft step speaker controls,
+15dB to -79dB with 1dB steps direct mute
■ Subwoofer
– Single-ended mono output
– Independent soft step level control, +15dB
to -79dB with 1dB steps
■ Mute functions
– Direct mute
– Digitally controlled SoftMute with 3
programmable mute-times
(0.48 ms / 0.96 ms /123 ms)
Description
The TDA7418 includes a high performance audio
processor with fully integrated 3-Band filters to
process signals at audible frequencies. The digital
control allows a full programming of the
audioprocessor and filters characteristics.
Order code Temp range, °CPackage Packing
TDA7418 -40 to +85 SO20 Tube
TDA7418TR -40 to +85 SO20 Tape and reel
November 2008 Rev 3 1/29
www.st.com
1
Contents TDA7418
Contents
1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Connection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Pin list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Electrical specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Description of the audioprocessor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1 Input stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2 AutoZero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.3 Loudness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3.1 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3.2 Peak frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3.3 Low and high frequency boost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3.4 Flat mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.4 SoftMute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.5 SoftStep volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.6 Bass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.6.1 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.6.2 Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.6.3 Quality factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.6.4 DC mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.7 Middle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.7.1 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.7.2 Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.7.3 Quality factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.8 Treble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.8.1 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.8.2 Center frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.9 Speaker attenuator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2/29
TDA7418 Contents
4.10 Subwoofer attenuator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.11 MUX output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.12 Audioprocessor testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5I
2
C bus specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.1 Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.1.1 Receive mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.1.2 Transmission mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.1.3 Reset condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.2 Subaddress (receive mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.3 Data byte specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3/29
List of tables TDA7418
List of tables
Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Table 2. Pin list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 3. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 4. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 5. Registers of all subaddresses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 6. Subaddress (receive mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 7. Input selector /gain (0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 8. Loudness (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 9. Volume / speaker attenuation (2,7,8,9,10,11). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 10. Treble filter (3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 11. Middle filter (4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 12. Bass filter (5). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 13. Middle / bass Fc select (6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 14. Soft mute and soft step time (12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 15. Testing audio processor (13) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 16. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4/29
TDA7418 List of figures
List of figures
Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 2. Pin out. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 3. Input stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 4. Loudness attenuation @ f
Figure 5. Loudness center frequencies @ Attn. = 15dB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 6. Loudness attenuation, fc = 2.4kHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 7. Softmute timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 8. SoftStep timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 9. Bass control @ f
= 80Hz, Q = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
C
Figure 10. Bass center frequencies @ Gain = 15dB, Q = 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 11. Bass quality factors @ Gain = 14dB, f
Figure 12. Bass normal and DC mode @ Gain = 14dB, f
Figure 13. Middle control @ f
= 1 kHz, Q = 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
C
Figure 14. Middle center frequencies @ Gain = 14dB, Q = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 15. Bass quality factors @ Gain = 14dB, f
Figure 16. Treble control @ f
= 17.5 kHz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C
Figure 17. Treble center frequencies @ Gain = 14dB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 18. MUX output configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 19. SO20 mechanical data and package dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
= 400Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
C
= 80Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
C
= 1kHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
C
= 80Hz . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
C
5/29
Block diagram TDA7418
1 Block diagram
Figure 1. Block diagram
OUTLF
16
Softstep
Mono Fader
Treble Middle Bass
Softstep
Volume
OUTRF
13
Softstep
Mono Fader
OUTLR
15
Softstep
Mono Fader
OUTRR
14
Softstep
Mono Fader
OUTSW
12
Softstep
Mono Fader
MIX
CBUS
2
DIGITAL CONTROL I
AC00057
SCL SDA
17
MUTE/MUXOUT
SoftMute
Loudness
+
InGain
AutoZero
DIFFL 7
SE1L 5
DIFFR 9
DIFFG 8
6/29
INPUT
MULTIPLEXER
SE2L 3
SE1R 6
3
7 6 18 19
SUPPLY
VDD GND CREF
SE3L 1
SE2R 4
SE3R 2
TDA7418 Pin description
2 Pin description
2.1 Connection diagram
Figure 2. Pin out
2.2 Pin list
Table 2. Pin list
No. Pin Name Description I/O
1 SE3L Single-ended input 3 left channel I
2 SE3R Single-ended input 3 right channel I
3 SE2L Single-ended input 2 left channel I
4 SE2R Single-ended input 2 right channel I
5 SE1L Single-ended input 1 left channel I
6 SE1R Single-ended input 1 Right channel I
7 DIFFL Pseudo differential stereo input left I
8 DIFFG Pseudo differential stereo input common I
9 DIFFR Pseudo differential stereo input right I
10 CREF Reference capacitor O
11 GND Ground S
12 OUTSW Subwoofer output O
13 OUTRF Front right output O
14 OUTRR Rear right output O
15 OUTLR Rear left output O
16 OUTLF Front left output O
17 MUTE / MUXOUT External mute pin / MUX output I
18 SCL I
19 SDA I
20 VDD Supply S
SE3L
SE3R
SE2L
SE2R
SE1L
SE1R
DIFFL
DIFFG
DIFFR OUTSW
CREF GND
2
3
4
5
6
7
8
9
10
2
C bus clock I
2
C bus data I/O
20
19
18
17
16
15
14
13
12
11
VDD1
SDA
SCL
MUTE/MUXOUT
OUTLF
OUTLR
OUTRR
OUTRF
AC00058
7/29
Electrical specification TDA7418
3 Electrical specification
3.1 Absolute maximum ratings
Table 3. Absolute maximum ratings
Symbol Parameter Value Unit
V
Supply voltage for V
S
CC
(1)
for other pins
-0.4 to 10.2
-0.4 to VCC + 0.4
V
T
T
V
ESD
V
ESD
V
ESD
1. Reference level is GND.
Operating temperature range -40 to +85 °C
op
Storage temperature -55 to +150 °C
stg
ESD protection (Human Body Model) ±2000 V
ESD protection (Machine Model) ±200 V
ESD protection (Change Device Model) ±750 V
3.2 Electrical characteristics
S
CL
IN
DC
V
= 8.5 V; T
S
S
Supply voltage 8 8.5 10 V
= 25 °C; RL= 10 kΩ; all gains = 0 dB; f = 1 kHz; unless otherwise specified
amb
Supply current 18 25 32 mA
in
Input resistance All single ended inputs 70 100 130 kΩ
Clipping level 1.8 2 V
Input separation 80 100 dB
Min. input gain -0.5 0 0.5 dB
Max. input gain 14 15 16 dB
Step resolution 0.5 1 1.5 dB
Adjacent gain steps -5 1 5 mV
DC steps
G
MIN to GMAX
-30 4 30 mV
Remaining offset with AutoZero 0.5 mV
Table 4. Electrical characteristics
Symbol Parameter Test condition Min. Typ. Max. Unit
Supply
V
I
Input selector
R
V
S
G
IN MIN
G
IN MAX
G
STEP
V
V
offset
Differential stereo inputs
RMS
Rin Input resistance Differential 70 100 130 kΩ
CMRR Common mode rejection ratio
=1 V
CM
=1 V
V
CM
@ 1kHz 40 60 dB
RMS
@ 10kHz 40 60 dB
RMS
V
8/29
TDA7418 Electrical specification
Table 4. Electrical characteristics (continued)
V
= 8.5 V; T
S
Symbol Parameter Test condition Min. Typ. Max. Unit
= 25 °C; RL= 10 kΩ; all gains = 0 dB; f = 1 kHz; unless otherwise specified
amb
e
No
Output noise @ speaker outputs
Loudness control
A
A
f
MAX
STEP
Peak
Max. attenuation -16 -15 -14 dB
Step resolution 0.5 1 1.5 dB
Peak frequency
Volu m e c o n tr o l
G
A
A
V
MAX
MAX
STEP
E
A
E
T
DC
Max. gain 14 15 16 dB
Max. attenuation -84 -79 -74 dB
Step resolution 0.5 1 1.5 dB
Attenuation set error
Tracking error 2 dB
DC steps
Soft mute
(1)
20Hz-20kHz,flat;
all stages 0dB
f
P1
f
P2
f
P4
360 400 440 Hz
720 800 880 Hz
2.1 2.4 2.7 kHz
12 20 μV
G = -20 to +15dB -1 0 1 dB
G = -79 to -20dB -4 0 3 dB
Adjacent Attenuation Steps -3 0.1 3 mV
From 0dB to G
MIN
-10 0.5 10 mV
A
MUTE
T
V
TH Low
V
TH High
R
PU
V
PU
D
Mute attenuation 80 100 dB
Delay time
Low threshold for SM pin 0.7 V
High threshold for SM pin 2.7 V
Internal pull-up resistor 32 45 58 kΩ
Internal pull-up voltage 3.3 V
Bass control
fc Center frequency
(1)
T1 0.48 ms
T2 0.96 ms
T3 123 ms
f
C1
f
C2
f
C3
f
C4
54 60 66 Hz
72 80 88 Hz
90 100 110 Hz
180 200 220 Hz
9/29
Electrical specification TDA7418
Table 4. Electrical characteristics (continued)
V
= 8.5 V; T
S
Symbol Parameter Test condition Min. Typ. Max. Unit
= 25 °C; RL= 10 kΩ; all gains = 0 dB; f = 1 kHz; unless otherwise specified
amb
Q
BASS
C
RANGE
A
STEP
DC
GAIN
Quality factor
Control range ±14 ±15 ±16 dB
Step resolution 0.5 1 1.5 dB
Bass-DC-gain
Middle control
C
RANGE
A
STEP
Control range ±14 ±15 ±16 dB
Step resolution 0.5 1 1.5 dB
fc Center frequency
Q
BASS
Quality factor
Treble control
(1)
(1)
(1)
Q
1
Q
2
Q
3
Q
4
0.9 1 1.1
1.1 1.25 1.4
1.3 1.5 1.7
1.8 2 2.2
DC = off 0 dB
DC = on 3.5 4.4 6 dB
f
C1
f
C2
f
C3
f
C4
Q
1
Q
2
Q
3
Q
4
400 500 600 Hz
0.8 1 1.2 kHz
1.2 1.5 1.8 kHz
22.5 3kHz
0.45 0.5 0.55
0.65 0.75 0.85
0.9 1 1.1
1.1 1.25 1.4
C
RANGE
A
STEP
fc Center frequency
Clipping level ±14 ±15 ±16 dB
Step resolution 0.5 1 1.5 dB
f
C1
f
(1)
C2
f
C3
f
C4
Speaker attenuator
G
A
A
STEP
A
MUTE
V
MAX
MAX
E
E
DC
Max. gain 14 15 16 dB
Max. attenuation -84 -79 -74 dB
Step resolution 0.5 1 1.5 dB
Mute attenuation 80 90 dB
Attenuation set error 2 dB
DC steps Adjacent attenuation steps -5 0.1 5 mV
10/29
81012kHz
10 12.5 15 kHz
12 15 18 kHz
14 17.5 21 kHz
TDA7418 Electrical specification
Table 4. Electrical characteristics (continued)
V
= 8.5 V; T
S
Symbol Parameter Test condition Min. Typ. Max. Unit
Audio outputs
= 25 °C; RL= 10 kΩ; all gains = 0 dB; f = 1 kHz; unless otherwise specified
amb
Clipping level d = 0.3% 1.8 2 V
Output impedance 30 100 Ω
Output load resistance 2 kΩ
Output load capacitor 10 nF
DC voltage level 3.8 4.0 4.2 V
R
V
OUT
R
C
V
CL
L
L
DC
Subwoofer attenuator
G
A
A
STEP
A
MUTE
V
MAX
MAX
E
E
DC
Max. gain 14 15 16 dB
Max. attenuation -84 -79 -74 dB
Step resolution 0.5 1 1.5 dB
Mute attenuation 80 90 dB
Attenuation set error 2 dB
DC steps Adjacent attenuation steps -5 0.1 5 mV
General
e
NO
Output noise
S/N Signal to noise ratio all gain = 0dB flat; Vo=2V
DDistortion V
S
C
1. Min. and max. values are calculated according to simulation results; functionality is guaranteed by measuring a directly
correlated parameter.
Channel separation left/right 80 90 dB
BW=20Hz to 20 kHz all gain =
0dB
RMS
IN
=1V
; all stages 0dB 0.005 0.100 %
RMS
12 20 μV
100 dB
RMS
11/29
Description of the audioprocessor TDA7418
4 Description of the audioprocessor
4.1 Input stages
In the basic configuration, one stereo pseudo differential (programmable as single-ended
input) and three single-ended stereo inputs are available.
Pseudo differential stereo input (PD/SE4)
The PD input is implemented as a buffered pseudo differential stereo stage with 100kΩ
input-impedance at each input. The attenuation is fixed to -3dB in order to adapt the
incoming signal level. It is also configurable as single-ended input.
Single-ended stereo input (SE1, SE2, SE3)
The input-impedance at each input is 100kΩ and the attenuation is fixed to -3dB for
incoming signals.
Figure 3. Input stage
4.2 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 input source is changed and needs max. 0.6ms
for the alignment. To avoid audible clicks the Audio processor is muted before the loudness
stage during this time.
QD_L/SE4_L
QD_G
QD_R/SE4_R
SE1_L
SE1_R
SE2_L
SE2_R
SE3_L
SE3_R
QD/SE4
SE1
SE2
SE3
QD/SE4
SE1
SE2
SE3
Input
Selector
In Gain
AutoZero-remain
In some cases, for example if the µP is executing a refresh cycle of the IIC-Busprogramming, it is not useful to start a new AutoZero-action because no new source is
12/29
TDA7418 Description of the audioprocessor
selected and an undesired mute would appear at the outputs. For such applications, it can
be switched in the AutoZero-Remain-Mode (Bit 6 of the subaddress-byte). If this bit is set to
high, the AutoZero will not be invoked and the old adjustment-value remains.
4.3 Loudness
There are four parameters programmable in the loudness stage:
4.3.1 Attenuation
Figure 4 shows the attenuation as a function of frequency at fC = 400Hz
Figure 4. Loudness attenuation @ f
4.3.2 Peak frequency
Figure 5 shows the four possible peak-frequencies at 400, 800 and 2400Hz
Figure 5. Loudness center frequencies @ Attn. = 15dB
= 400Hz.
C
13/29
Description of the audioprocessor TDA7418
4.3.3 Low and high frequency boost
Figure 6 shows the different Loudness shapes in low & high frequency boost.
Figure 6. Loudness attenuation, fc = 2.4kHz
4.3.4 Flat mode
In flat mode the loudness stage works as a 0dB to -15dB attenuator.
4.4 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
2
the I
C-bus. This slope is realized in a special S-shaped curve to mute slow in the critical
regions (see Figure 7).
For timing purposes the Bit0 of the I
until the end of demuting.
Figure 7. Softmute timing
EXT.
MUTE
+SIGNAL
REF
-SIGNAL
2
C-bus output register is set to 1 from the start of muting
1
1
2
C BUS
I
OUT
1. Please notice that a started Mute-action is always terminated and could not be interrupted by a change of
the mute-signal
14/29
D97AU634
Time
TDA7418 Description of the audioprocessor
4.5 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 audio signal. With the SoftStep-feature both kinds of clicks could be reduced to a
minimum and are no more audible.
Eight programmable softstep time from one step to the next are user selectable.
Figure 8. SoftStep timing
V
OUT
1dB
0.5dB
1. For steps more than 1dB the SoftStep mode should be deactivated because it could generate 1dB error
step during the blend-time.
4.6 Bass
There are four parameters programmable in the bass stage:
4.6.1 Attenuation
Figure 9 shows the attenuation as a function of frequency at a center frequency of 80Hz.
Figure 9. Bass control @ f
-0.5dB
-1dB
SS Time
= 80Hz, Q = 1
C
Time
D00AU1170
15/29
Description of the audioprocessor TDA7418
4.6.2 Center frequency
Figure 10 shows the four possible center frequencies 60, 80, 100 and 200Hz.
Figure 10. Bass center frequencies @ Gain = 15dB, Q = 1
4.6.3 Quality factors
Figure 11 shows the four possible quality factors 1, 1.25, 1.5 and 2.
Figure 11. Bass quality factors @ Gain = 14dB, f
4.6.4 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 12. Bass normal and DC mode @ Gain = 14dB, f
= 80Hz
C
= 80Hz
C
1. The center frequency, Q and DC-mode can be set fully independently.
16/29
TDA7418 Description of the audioprocessor
4.7 Middle
There are three parameters programmable in the middle stage:
4.7.1 Attenuation
Figure 13 shows the attenuation as a function of frequency at a center frequency of 1kHz.
Figure 13. Middle control @ f
4.7.2 Center frequency
Figure 14 shows the four possible center frequencies 500Hz, 1kHz, 1.5kHz and 2.5kHz.
Figure 14. Middle center frequencies @ Gain = 14dB, Q = 1
= 1 kHz, Q = 1
C
4.7.3 Quality factors
Figure 15 shows the four possible quality factors 0.5, 0.75, 1 and 1.5.
Figure 15. Bass quality factors @ Gain = 14dB, f
= 1kHz
C
17/29
Description of the audioprocessor TDA7418
4.8 Treble
There are two parameters programmable in the treble stage:
4.8.1 Attenuation
Figure 16 shows the attenuation as a function of frequency at a center frequency of
17.5kHz.
Figure 16. Treble control @ f
4.8.2 Center frequency
Figure 17 shows the four possible center frequencies 10k, 12.5k, 15k and 17.5kHz.
Figure 17. Treble center frequencies @ Gain = 14dB
= 17.5 kHz
C
4.9 Speaker attenuator
The four speakers have independent soft step speaker controls. And their attenuators can
be adjusted from +15dB to -79dB with 1dB steps.
4.10 Subwoofer attenuator
The Subwoofer output is a single ended mono output. The attenuator is exactly the same
like the other speakers.
18/29
TDA7418 Description of the audioprocessor
9
4.11 MUX output
It provides a mono signal output (before tone filters) at Mute/MUX pin, used for external level
meter / spectrum analyzer.
The mute pin can be configured as MUX output (I
as MUX output, the output voltage is (InGainL+InGainR)/2 with -3dB attenuation.
Figure 18. MUX output configuration
InGainL
2
C Byte13_D7D1). When it is configured
InGainR
4.12 Audioprocessor testing
In the test mode, which can be activated by setting bit D7 of the IIC subaddress byte and bit
D0 of the testing audioprocessor byte, several internal signals are available at the SE2R pin.
In this mode, the input resistance of 100kOhm is disconnected from the pin. Internal signals
available for testing are listed in the data-byte specification.
+
MUTE/MUX = (InGainL+InGainR)/2 * (-3dB)
AC0005
19/29
I2C bus specification TDA7418
5 I2C bus specification
5.1 Interface protocol
The interface protocol comprises:
– a start condition (S)
– a chip address byte (the LSB determines read/write transmission)
– a subaddress byte
– a sequence of data (N-bytes + acknowledge)
– a stop condition (P)
– the max. clock speed is 500kbits/s
5.1.1 Receive mode
S 1 0 0 0 1 0 0 R/W ACK TS AZ AI A4 A3 A2 A1 A0 ACK DATA ACK P
S = Start
R/W = "0" -> Receive Mode (Chip can be programmed by μP)
"1" -> Transmission Mode (Data could be received by μP)
ACK = Acknowledge
P = Stop
TS = Testing mode
AZ = Auto zero remain
AI = Auto increment
5.1.2 Transmission mode
S1000100R/WACKXXXXXXXSMACKP
SM = Soft mute activated for main channel
X = Not Used
The transmitted data is automatic updated after each ACK. Transmission can be repeated
without new chip address.
5.1.3 Reset condition
A Power-On-Reset is invoked if the Supply-Voltage is below than 2.5V. After that the
following data is written automatically into the registers of all subaddresses:
Table 5. Registers of all subaddresses
MSB LSB
11111110
20/29
TDA7418 I2C bus specification
5.2 Subaddress (receive mode)
Table 6. Subaddress (receive mode)
MSB LSB
Function
I2 I1 I0 A4 A3 A2 A1 A0
Testing Mode
0
1
0
1
0
1
0 0 0 0 0 Main Source Selector
0 0 0 0 1 Loudness
0 0 0 1 0 Volume
000 11Treble
Off
On
Auto Zero Remain
Off
On
Auto Increment Mode
Off
On
001 00Middle
001 01Bass
0 0 1 1 0 Middle/ Bass Fc Select
0 0 1 1 1 Speaker Attenuator Left Front
0 1 0 0 0 Speaker Attenuator Left Rear
0 1 0 0 1 Speaker Attenuator Right Rear
0 1 0 1 0 Speaker Attenuator Right Front
0 1 0 1 1 Subwoofer Attenuator
0 1 1 0 0 Soft Mute / Soft Step
0 1 1 0 1 Testing Audio Processor
21/29
I2C bus specification TDA7418
5.3 Data byte specification
Table 7. Input selector /gain (0)
MSB LSB
Function
D7 D6 D5 D4 D3 D2 D1 D0
Source Selector
0
0
:
1
1
0
0
1
1
0
0
:
:
1
1
0
1
Table 8. Loudness (1)
0
0
0
0
1
0
1
:
0
1
0
0
1
1
X
0
1
0
1
X
PD/SE4
SE1
SE2
SE3
mute
Input Gain
0dB
1dB
:
14dB
15dB
Diffin Mode
Single Ended Stereo
Differential Stereo
MSB LSB
D7 D6 D5 D4 D3 D2 D1 D0
00
0
1
1
0
0
:
1
1
0
1
0
1
0
0
:
1
1
0
0
:
1
1
0
1
:
0
1
0
1
0
1
Function
Attenuation
0dB
-1dB
:
-14dB
-15dB
Filter/Center Frequency
Off (Flat) D6 must be = 0
400Hz
800Hz
2400Hz
Shape
Low Boost
Low & HighBoost
Loudness Soft Step
on
off
22/29
TDA7418 I2C bus specification
Table 9. Volume / speaker attenuation (2,7,8,9,10,11)
MSB LSB
Function
D7 D6 D5 D4 D3 D2 D1 D0
Gain/Attenuation
0
0
:
0
0
0
0
:
0
0
:
1
1
1
0
1
Table 10. Treble filter (3)
0
0
:
0
0
0
0
:
0
1
:
0
0
1
0
0
:
0
0
1
1
:
1
0
:
1
1
x
1
1
:
0
0
0
0
:
1
0
:
1
1
x
1
1
:
0
0
0
0
:
1
0
:
1
1
x
1
1
:
0
0
0
0
:
1
0
:
1
1
x
1
+15dB
0
+14dB
:
:
1
+1dB
0
0dB
0
0dB
1
-1dB
:
:
1
-15dB
0
-16dB
:
:
0
-78dB
1
-79dB
x
Mute
Volume Soft Step
on
off
MSB LSB
D7 D6 D5 D4 D3 D2 D1 D0
Gain/Attenuation
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
-15dB
1
-14dB
:
:
0
-1dB
1
0dB
1
0dB
0
+1dB
:
:
1
+14dB
0
+15dB
Treble Center Frequency
0
0
1
1
0
1
0
1
10.0kHz
12.5kHz
15.0kHz
17.5kHz
1 Must be “1”
Function
23/29
I2C bus specification TDA7418
Table 11. Middle filter (4)
MSB LSB
Function
D7 D6 D5 D4 D3 D2 D1 D0
Gain/Attenuation
0
0
0
0
1
1
1
1
0
0
1
1
0
1
0
1
0
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
-15dB
1
-14dB
:
:
0
-1dB
1
0dB
1
0dB
0
+1dB
:
:
1
+14dB
0
+15dB
Middle Q Factor
0.5
0.75
1
1.25
Middle Soft Step
on
off
24/29
TDA7418 I2C bus specification
Table 12. Bass filter (5)
MSB LSB
Function
D7 D6 D5 D4 D3 D2 D1 D0
Gain/Attenuation
0
0
:
0
0
1
1
:
1
1
0
0
1
1
0
1
0
1
0
1
Table 13. Middle / bass Fc select (6)
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
-15dB
1
-14dB
:
:
0
-1dB
1
0dB
1
0dB
0
+1dB
:
:
1
+14dB
0
+15dB
Bass Q Factor
1.0
1.25
1.5
2.0
Bass Soft Step
on
off
MSB LSB
D7 D6 D5 D4 D3 D2 D1 D0
Middle Center Frequency
0
0
1
1
0
500Hz
1
1kHz
0
1.5kHz
1
2.5kHz
Bass Center Frequency
0
0
1
1
0
1
0
1
60Hz
80Hz
100Hz
200Hz
Bass DC Mode
0
1
off
on
Smoothing Filter
0
1
off
on
X X Not used
Function
25/29
I2C bus specification TDA7418
Table 14. Soft mute and soft step time (12)
MSB LSB
D7 D6 D5 D4 D3 D2 D1 D0
Soft Mute
0
on
1
off
Soft Mute Time
0
0
1
0
1
X
0.48ms
0.96ms
123ms
Soft Step Time
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0.16ms
0.32ms
0. 64ms
1.28ms
2.56ms
5.12ms
10.24ms
20.48ms
AZ function
0
1
off
on
X Not used
Table 15. Testing audio processor (13)
MSB LSB
D7 D6 D5 D4 D3 D2 D1 D0
Audio Processor Testing Mode
0
off
1
on
Test Multiplexer
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
InMuxOutR
LoudOutR
VolumeOutR
VBG1.26
REF5V5
SSCLK
SMCLK
Clk200kHz
xNot Used
Schlock
0
1
Normal
Fast Mode
MUTE Pin Config.
0
1
1
x
0
1
MUX output
External clock
Mute (normal)
Function
Function
26/29
TDA7418 Package information
6 Package information
In order to meet environmental requirements, ST (also) offers these devices in ECOPACK®
packages. ECOPACK
®
packages are lead-free. The category of second Level Interconnect
is marked on the package and on the inner box label, in compliance with JEDEC Standard
JESD97. The maximum ratings related to soldering conditions are also marked on the inner
box label.
ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com.
Figure 19. SO20 mechanical data and package dimensions
DIM.
A 2.35 2.65 0.093 0.104
A1 0.10 0.30 0.004 0.012
B 0.33 0.51 0.013 0.200
C 0.23 0.32 0.009 0.013
(1)
D
E 7.40 7.60 0.291 0.299
e 1.27 0.050
H 10.0 10.65 0.394 0.419
h 0.25 0.75 0.010 0.030
L 0.40 1.27 0.016 0.050
k 0˚ (min.), 8˚ (max.)
ddd 0.10 0.004
(1) “D” dimensio n does not include mold flash, prot usions or gate
burrs. Mol d flash, prot usions or gat e burrs shal l not exceed
0.15mm per sid e.
mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
12.60 13.00 0.496 0.512
OUTLINE AND
MECHANICAL DATA
SO20
0016022 D
27/29
Revision history TDA7418
7 Revision history
Table 16. Document revision history
Date Revision Changes
15-Feb-2007 1 Initial release.
23-Oct-2008 2 Updated Table 6: Subaddress (receive mode) on page 21.
03-Nov-2008 3 Corrected Table 6: Subaddress (receive mode) on page 21.
28/29
TDA7418
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