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TDA7437N
October 2003
s
INPUT MULTIPLEXER
FOUR STEREO, ONE MONO INPUT, AND
ONE DIFFERENTIAL INPUT
SELECTABLE INPUT GAIN FOR OPTIMAL
ADAPTATION TO DIFFERENT SOURCES
s
FULLY PROGRAMMABLE LOUDNESS
FUNCTION
s
VOLUME CONTROL IN 1dB STEPS
INCLUDING GAIN UP TO 16dB
s
ZERO CROSSING MUTE, SOFT MUTE AND
DIRECT MUTE
s
BASS AND TREBLE CONTROL
s
FOUR SPEAKER ATTENUATORS- FOUR
INDEPENDENT SPEAKERS CONTROL IN
1dB STEPS FOR BALANCE AND FADER
FACILITIES
s
PAUSE DETECTOR PROGRAMMABLE
THRESHOLD
s
ALL FUNCTIONS PROGRAMMABLE VIA
SERIAL I
2
C BUS
DESCRIPTION
The audioprocessor TDA7437N is an upgrade of the
TDA731X audioprocessor family.
Due to a highly linear signal processing, using
CMOS-switching techniques instead of standard bi-
polar multipliers, very low distortion and very low
noise are obtained. Several new features like soft-
mute, and zero-crossing mute are implemented.The
soft Mute function can be activated in two ways:
1 Via serial bus (Mute byte, bit D0)
2 Directly on pin 28 through an I/O line of the
microcontroller
Very low DC stepping is obtained by use of a BIC-
MOS technology.
TQFP44
ORDERING NUMBER: TDA7437N
DIGITALLY CONTROLLED AUDIO PROCESSOR
PIN DESCRIPTION (Top view)
1
2
3
5
6
4
7
8
9
10
17
11
18 19 20 21 22
44 43 42 41
39
40
38 37 36 35 34
28
27
26
24
23
25
33
32
31
29
30
DIFF_R
DIFFGND_R
LOUD_R
IN_R
TREB_R
MUXOUT_R
MONO
STEREO3_R
STEREO2_R
STEREO4_R
STEREO1_R
LOUD_L
DIFFGND_L
DIFF_L
STEREO4_L
STEREO2_L
STEREO1_L
STEREO3_L
CSM
IN_L
MUXOUT_L
MID_RI
TREB-L
AGND
AVDD
DVDD
CREF
ADDR
SCL
SDA
DGND
PAUSE
OUT_LF
SMEXT
BASS_RO
BASS_RI
BASS_LI
MID_RO
BASS_LO
OUT_RF
OUT_LR
MID_LI
OUT_RR
MID_LO
D96AU435B
12 13 14 15 16
TDA7437N
2/23
ABSOLUTE MAXIMUM RATINGS
THERMAL DATA
QUICK REFERENCE DATA
Symbol
Parameter
Value
Unit
AV
DD
, DV
DD
Operating Supply Voltage
10.5
V
T
amb
Operating Ambient Temperature
-40 to 85
C
T
stg
Storage Temperature Range
-55 to 150
C
Symbol
Parameter
Value
Unit
R
th j-amb
Thermal Resistance Junction to pins
Max.
150
C/W
Symbol
Parameter
Min.
Typ.
Max.
Unit
AV
DD
, DV
DD
Supply Voltage (AVDD and DVDD must be at the same
potential)
6
9
10.2
V
V
CL
Max. input signal handling
2.1
2.6
Vrms
THD
Total Harmonic Distortion V = 1Vrms f = 1KHz
0.01
0.8
%
S/N
Signal to Noise Ratio
111
dB
S
C
Channel Separation f = 1KHz
95
dB
Input Gain 1dB step
0
15
dB
Volume Control 1dB step
-63
16
dB
Treble Control 2dB step
-14
+14
dB
Bass Control 2dB step
-14
+14
dB
Middle Control 2dB step
-14
+14
dB
Fader and Balance Control 1dB step
-79
0
dB
Loudness Control 1dB step
0
20
dB
Mute Attenuation
100
dB
3/23
TDA7437N
BLOCK DIAGRAM
STEREO1_L
SUPPLY
AVDD
AGND
TREBLE
BASS
MIDDLE
D95AU249B
I2
C BUS DECODER + LATCHES
SPKR
ATT
SPKR
ATT
TREBLE
BASS
MIDDLE
SPKR
ATT
SPKR
ATT
SDA
OUT_RR
OUT_RF
OUT_LR
OUT_LF
16
17
18
15
14
13
11
8
9
10
7
6
5
41
42
43
39
3
21
20
12
44
30
31
25
24
2
412
3
2
2
2
72
6
2
8
3
5
1
9
32
29
36
37
38
40
33
34
DIFF_R
VOLUME
+ LOUDN
VOLUME
+ LOUDN
MONO
STEREO2_L
STEREO4_R
ADDR
SCL
DIGGND
S-MUTE
S-MUTE
MUTE CONTROL
SOFT, ZERO
CSM
PAUSE
SMEXT
BASS_RI
BASS_RO)
MID_RI
MID_RO
TREB_R
CREF
LOUD_R
INGAIN
MULTIPLEXER
INGAIN
LOUD_L
STEREO3_L
STEREO4_L
DIFF_L
DIFFGND_L
STEREO1_R
STEREO2_R
STEREO3_R
DIFFGND_R
BASS_LI
BASS_LO
MID_LI
MID_LO
TREBL_L
MUXOUT_L
IN_L
MUXOUT_R
IN_R
4 x 470nF
2 x 4.7
F
2 x 4.7
F
5 x 470nF
DVDD
22
F
2.2
F
2.2
F
47nF
47nF
5.6nF
5.6nF
22nF
2.7K
18nF
100nF
5.6K
100nF
22nF
2.7K
18nF
100nF
5.6K
100nF
47nF
47nF
TDA7437N
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ELECTRICAL CHARACTERISTICS
(AV
DD
, DV
DD
= 9V; R
L
= 10K
; R
g
= 50
; T
amb
= 25C; all gains = 0dB; f = 1KHz. Refer to the test circuit,
unless otherwise specified.)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
INPUT SELECTOR (MONO AND STEREO INPUTS)
R
I
Input Resistance
pin 7 to 11 and 15 to 18
70
100
130
K
V
CL
Clipping
Level
d
0.3%
2.1
2.6
V
RMS
S
I
Input Separation
80
95
dB
R
L
Output Load Resistance
2
K
G
I MIN
Minimum Input Gain
-0.75
0
+0.75
dB
G
I MAX
Maximum Input Gain
14
15
16
dB
G
step
Step Resolution
0.5
1.0
1.5
dB
E
a
Set Error
-1.0
0
1.0
dB
V
DC
DC Steps
Adiacent Gain Steps
0.5
10
mV
G
IMIN
to G
IMAX
3
mV
DIFFERENTIAL INPUT (Pin 5, 6, 13, 14)
R
I
Input Resistance
Input selector BIT D4 = 0 (0dB)
10
15
20
K
Input selector BIT D4 = 1(-6dB)
14
20
26
K
CMRR
Common Mode Rejection Ratio
V
CM
= 1V
RMS
; f = 1KHz
45
70
dB
d
Distortion
V
I
= 1V
RMS
0.01
0.08
%
e
IN
Input Noise
20Hz to 20KHz; Flat; D6 = 0
5
V
G
DIFF
Differential Gain
D4 = 0
-1
0
1
dB
D4 = 1
-7
-6
-5
dB
VOLUME CONTROL
R
I
Input Resistance
Pin 2 and 20
31
44
57
K
G
MAX
Maximum Gain
15
16
17
dB
A
MAX
Maximum
Attenuation
61
63.75
66.5
dB
A
STEPC
Step Resolution Coarse Atten.
0.5
1.0
1.5
dB
E
A
Attenuation Set Error
G = 16 to -20dB
-1.0
0
1.0
dB
G = -20 to -63dB
-2.75
2.75
dB
E
t
Tracking Error
2
dB
V
DC
DC Steps
Adjacent Gain Steps
-5
+5
mV
Adjacent Attenuation Steps
-3
+3
mV
From 0dB to A
MAX
0.5
5
mV
LOUDNESS CONTROL (Pin 4, 12)
R
I
Internal Resistor
Loud = On
35
50
65
K
A
MAX
Maximum Attenuation
19
20
21
dB
A
step
Step Resolution
0.5
1
1.5
dB
ZERO CROSSING MUTE
V
TH
Zero Crossing Threshold(note 1)
WIN = 11
35
mV
WIN = 10
70
mV
WIN = 01
140
mV
WIN = 00
280
mV
A
MUTE
Mute Attenuation
80
100
dB
5/23
TDA7437N
V
DC
DC Step
0dB to Mute
0.1
3
mV
SOFT MUTE
A
MUTE
Mute Attenuation
50
65
dB
T
DON
ON Delay Time
C
CSM
= 22nF; 0 to -20dB; I = I
MAX
0.8
1.5
2.0
ms
C
CSM
= 22nF; 0 to -20dB; I = I
MIN
25
45
60
ms
T
DOFF
OFF Current
V
CSM
= 0V; I = I
MAX
20
40
60
mA
V
CSM
= 0V; I = I
MIN
2
A
R
INT
Pullup Resistor (pin 28)
(note 2)
100
K
V
SMH
(pin 28) Level High
3.5
V
V
SML
(pin 28) Level Low
Soft Mute Active
1
V
BASS CONTROL
C
range
Control Range
11.5
14
16
dB
A
step
Step Resolution
1
2
3
dB
R
g
Internal Feedback Resistance
31
44
57
K
MIDDLE CONTROL
C
range
Control Range
11.5
14
16
dB
A
step
Step Resolution
1
2
3
dB
R
g
Internal Feedback Resistance
17.5
25
32.5
K
TREBLE CONTROL
C
RANGE
Control Range
13
14
15
dB
A
step
Step Resolution
1
2
3
dB
SPEAKER ATTENUATORS
C
RANGE
Control
Range
79
dB
A
step
Step Resolution
A
V
= 0 to -40dB
0.5
1
1.5
dB
A
MUTE
Output Mute Attenuation
Data Word = 1111XXXX
80
100
dB
E
A
Attenuation Set Error
A
V
= 0 to -40dB
1.5
dB
V
DC
DC Steps
Adjacent Attenuation Steps
0.1
3
mV
AUDIO OUTPUT
V
clip
Clipping Level
d = 0.3%
2.1
2.6
Vrms
R
L
Output Load Resistance
2
K
R
O
Output Impedance
50
90
140
V
DC
DC Voltage Level
3.5
3.8
4.1
V
PAUSE DETECTOR
V
TH
Pause Threshold
WIN = 11
35
mV
WIN = 10
70
mV
WIN = 01
140
mV
WIN = 00
280
mV
I
DELAY
Pull-Up Current
15
25
35
A
V
THP
Pause Threshold
3.0
V
ELECTRICAL CHARACTERISTICS (continued)
(AV
DD
, DV
DD
= 9V; R
L
= 10K
; R
g
= 50
; T
amb
= 25C; all gains = 0dB; f = 1KHz. Refer to the test circuit,
unless otherwise specified.)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
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