TDA7342
DIGITALLY CONTROLLED AUDIO PROCESSOR
INPUT MULTIPLEXER
- TWO STEREO AND ONE MONO INPUTS
- ONE QUASI DIFFERENTIAL INPUT
- SELECTABLE INPUT GAIN FOR OPTIMAL
ADAPTATION TO DIFFERENT SOURCES
FULLY PROGRAMMABLE LOUDNESS
FUNCTION
VOLUME CONTROL IN 0.3dB STEPS IN-
CLUDING GAIN UP TO 20dB
ZERO CROSSING MUTE, SOFT MUTE AND
DIRECT MUTE
BASS AND TREBLE CONTROL
FOUR SPEAKER ATTENUATORS
- FOUR INDEPENDENT SPEAKERS
CONTROL IN 1.25dB STEPS FOR
BALANCE AND FADER FACILITIES
- INDEPENDENT MUTE FUNCTION
ALL FUNCTIONS PROGRAMMABLE VIA SE-
RIAL I
2
CBUS
DESCRIPTION
The audioprocessor TDA7342 is an upgrade of
the TDA731X audioprocessor family.
Due to a highly linear signal processing, using
CMOS-switching techniques instead of standard
bipolar multipliers, very low distortion and very
low noise are obtained. Several new features like
softmute, and zero-crossing mute are imple-
mented.
The soft Mute function can be activated in two
ways:
1 Via serial bus (Mute byte, bit D0)
2 Directly on pin 21 through an I/O line of the
microcontroller
Very low DC stepping is obtained by use of a
BICMOS technology.
October 2003
ORDERING NUMBER: TDA7342N
TQFP 32
1/14
13
12
10
11
L1
L2
L3
L1
L2
L3
M
7
8
5
R1
R2
R3
R1
R2
R3
M
M
CD GND
6
INPUT
SELECTOR
+ GAIN
LEFT
INPUTS
CD
RIGHT
INPUTS
SUPPLY
30
31
29
ZERO
CROSS +
MUTE
SOFT
MUTE
OUT(L)
IN(L)
16
15
LOUD+
VOL
ZERO
CROSS +
MUTE
LOUD+
VOL
BASS
BASS
LOUD(L)
9
TREBLE
TREBLE
10
F C9
31
4
CSM
OUT(R)
CREF
IN(R)
2
4
LOUD(R)
BOUT(L)
BIN(L)
18
17
BOUT(R)
BIN(R)
20
19
1
TREBLE(R)
SPKR
ATT
MUTE
SPKR
ATT
MUTE
SPKR
ATT
MUTE
SPKR
ATT
MUTE
TREBLE(L)
32
23
28
27
26
24
25
22
OUT
LEFT FRONT
OUT
LEFT REAR
SCL
SDA
DIGGND
OUT
RIGHT FRONT
OUT
RIGHT REAR
D94AU104B
BUS
SERIAL BUS DECODER + LATCHES
MONO INPUT
C1
C2
C6
C3
C7
C8
C4
C5
C10
C12
47nF
CSM
47nF
C14
100nF
C15
100nF
4.7K
C16
2.7nF
C19 2.7nF
C18
100nF
C17 100nF
C13 47nF
C11
R2
4.7K
21
SM
V
S
R1
BLOCK DIAGRAM
TDA7342
2/14
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
S
Operating Supply Voltage
10.5
V
T
amb
Operating Ambient Temperature
-40 to 85
C
T
stg
Storage Temperature Range
-55 to 150
C
THERMAL DATA
Symbol
Parameter
Value
Unit
R
th j-amb
Thermal Resistance Junction-pins
150
C/W
QUICK REFERENCE DATA
Symbol
Parameter
Min.
Typ.
Max.
Unit
V
S
Supply Voltage
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
0.08
%
S/N
Signal to Noise Ratio
106
dB
S
C
Channel Separation f = 1KHz
100
dB
Volume Control 0.3dB step
-59.7
20
dB
Treble Control 2dB step
-14
+14
dB
Bass Control 2dB step
-10
+18
dB
Fader and Balance Control 1.25dB step
-38.75
0
dB
Input Gain 3.75dB step
0
11.25
dB
Mute Attenuation
100
dB
1
2
3
5
6
4
7
8
11 12 13 14 15 16
32
30
31
29 28 27 26 25
19
18
17
24
23
22
20
21
IN R2
IN R3
LOUD R
IN R
TR R
OUT R
IN R1
MONO
LOUD L
IN L3
CD GND
IN L2
IN L1
CSM
IN L
OUT L
TR L
V
S
GND
SM
CREF
SCL
SDA
DIG GND
BIN R
BOUT L
BIN L
OUT LF
OUT RF
OUT LR
BOUT R
OUT RR
D94AU105A
9
10
PIN CONNECTION
TDA7342
3/14
ELECTRICAL CHARACTERISTICS (V
S
= 9V; R
L
= 10K
; R
g
= 50
; T
amb
= 25
C; all gains = 0dB;
f = 1KHz. Refer to the test circuit, unless otherwise specified.)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
INPUT SELECTOR
R
I
Input Resistance
70
100
130
K
V
CL
Clipping Level
d
0.3%
2.1
2.6
V
RMS
S
I
Input Separation
80
100
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
10.25
11.25
12.25
dB
G
step
Step Resolution
2.75
3.75
4.75
dB
e
N
Input Noise
20Hz to 20 KHz unweighted
2.3
V
V
DC
DC Steps
Adiacent Gain Steps
1.5
10
mV
G
IIN
to G
IMAX
3
mV
DIFFERENTIAL INPUT ( IN 3)
R
I
Input Resistance
Input selector BIT D6 = 0 (0dB)
10
15
20
K
Input selector BIT D6 = 1(-6dB)
14
20
30
K
CMRR
Common Mode Rejection Ratio
V
CM
= 1V
RMS
; f =1KHz
48
75
dB
f = 10KHz
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
D6 = 0
-1
0
1
dB
D6 = 1
-7
-6
-5
dB
VOLUME CONTROL
R
I
Input Resistance
35
50
K
G
MAX
Maximum Gain
18.75
20
21.25
dB
A
MAX
Maximum Attenuation
57.7
59.7
62.7
dB
A
STEPC
Step Resolution Coarse Atten.
0.5
1.25
2.0
dB
A
STEPF
Step Resolution Fine Attenuation
0.11
0.31
0.51
dB
E
A
Attenuation Set Error
G = 20 to -20dB
-1.25
0
1.25
dB
G = -20 to -58dB
-3
2
dB
E
t
Tracking Error
2
dB
V
DC
DC Steps
Adiacent Attenuation Steps
-3
0
3
mV
From 0dB to A
MAX
0.5
5
mV
LOUDNESS CONTROL
R
I
Internal Resistor
Loud = On
35
50
65
K
A
MAX
Maximum Attenuation
17.5
18.75
20.0
dB
A
step
Step Resolution
0.5
1.25
2.0
dB
TDA7342
4/14
ELECTRICAL CHARACTERISTICS (continued.)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
ZERO CROSSING MUTE
V
TH
Zero Crossing Threshold
(note 1)
WIN = 11
20
mV
WIN = 10
40
mV
WIN = 01
80
mV
WIN = 00
160
mV
A
MUTE
Mute Attenuation
80
100
dB
V
DC
DC Step
0dB to Mute
0
3
mV
SOFT MUTE
A
MUTE
Mute Attenuation
45
60
dB
T
DON
ON Delay Time
C
CSM
= 22nF; 0 to -20dB; I = I
MAX
0.7
1
1.7
ms
C
CSM
= 22nF; 0 to -20dB; I = I
MIN
20
35
55
ms
T
DOFF
OFF Current
V
CSM
= 0V; I = I
MAX
25
50
75
A
V
CSM
= 0V; I = I
MIN
1
A
V
THSM
Soft Mute Threshold
1.5
2.5
3.5
V
R
INT
Pullup Resistor (pin 21)
(note 2)
35
50
65
K
V
SMH
(pin 21) Level High
3.5
V
V
SML
(pin 21) Level Low
Soft Mute Active
1
V
BASS CONTROL
B
BOOST
Max Bass Boost
15
18
20
dB
B
CUT
Max Bass Cut
-8.5
-10
-11.5
dB
A
step
Step Resolution
1
2
3
dB
R
g
Internal Feedback Resistance
45
65
85
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
35
37.5
40
dB
A
step
Step Resolution
0.5
1.25
2.00
dB
A
MUTE
Output Mute Attenuation
Data Word = XXX11111
80
100
dB
E
A
Attenuation Set Error
1.25
dB
V
DC
DC Steps
Adjacent Attenuation Steps
0
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
30
100
V
DC
DC Voltage Level
3.5
3.8
4.1
V
TDA7342
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