ST TDA7342 User Manual
Features
■ 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 including 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 serial I
2
C bus
Description
The audioprocessor TDA7342 is an upgrade of
the TDA731X audioprocessor family.
TDA7342
Digitally controlled audio processor
LQFP32
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
implemented. 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.
Order codes
Part number Package Packing
TDA7342N LQFP32 Tube
TDA7342NTR LQFP32 Tape and reel
November 2006 Rev 2 1/20
www.st.com
1
Contents TDA7342
Contents
1 Block diagram and pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 I2C Bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 Data validity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2 Start and stop conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3 Byte format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.4 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.5 Transmission without acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4 Software specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1 Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2 Auto increment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.3 Transmitted data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.4 Data byte specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2/20
TDA7342 List of tables
List of tables
Table 1. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 2. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 3. Quick reference data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 4. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 5. Subaddress (receive mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 6. Send mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 7. Input selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 8. Loudness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Table 9. Mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Table 10. Speaker attenuators (LF, LR, RF, RR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 11. Bass/Treble. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 12. Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 13. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3/20
List of figures TDA7342
List of figures
Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 2. Pin connections (Top view). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 3. Data validity on the I2C BUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 4. Timing diagram of I2C BUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 5. Acknowledge on the I2C BUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 6. Interface protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 7. LQFP32 Mechanical data & package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4/20
TDA7342 Block diagram and pin descriptions
1 Block diagram and pin descriptions
1.1 Block diagram
Figure 1. Block diagram
LEFT
INPUTS
CD
MONO INPUT
RIGHT
INPUTS
C8
C4
C1
C2
C6
CD GND
C3
C7
C5
13
L1
12
L2
11
L3
10
5
R3
M
8
R2
6
R1
7
V
S
SUPPLY
30 31 29
L1
L2
M
L3
R3
M
R2
R1
10μF C9
INPUT
SELECTOR
+ GAIN
VOL
VOL
CSMOUT(R)CREF
CSM
47nF
21
SM
SOFT
MUTE
C17 100nF
BOUT(L)
18 17
20 19 1
C11
ZERO
CROSS +
MUTE
ZERO
CROSS +
MUTE
2 4
IN(R)
C10
C13 47nF
LOUD(L)
LOUD(R)
C12
47nF
9
LOUD+
LOUD+
OUT(L) IN(L)
16 15
314
R2
4.7K
100nF
BIN(L)
32
BASS
TREBLE
SERIAL BUS DECODER + LATCHES
BASS
TREBLE
BOUT(R) BIN(R)
C14
C15
100nF
100nF
4.7K
R1
C19 2.7nFC18
TREBLE(L)
TREBLE(R)
C16
2.7nF
SPKR
ATT
MUTE
SPKR
ATT
MUTE
SPKR
ATT
MUTE
SPKR
ATT
MUTE
25
23
28
27
26
24
22
D94AU104B
OUT
LEFT FRONT
OUT
LEFT REAR
SCL
SDA
DIGGND
OUT
RIGHT FRONT
OUT
RIGHT REAR
BUS
1.2 Pin description
Figure 2. Pin connections (Top view)
TR R
IN R
OUT R
LOUD R
IN R3
IN R2
IN R1
MONO
S
GND
TR L
V
CREF
SCL
SDA
DIG GND
OUT LF
323031 29 28 27 26 25
1
2
3
4
5
6
7
8
11 12 13 14 15 16
910
IN L3
LOUD L
CD GND
IN L2
IN L1
CSM
IN L
24
23
22
21
20
19
18
17
OUT L
OUT RF
OUT LR
OUT RR
SM
BOUT R
BIN R
BOUT L
BIN L
D94AU105A
5/20
Electrical specifications TDA7342
2 Electrical specifications
2.1 Absolute maximum ratings
Table 1. Absolute maximum ratings
Symbol Parameter Value Unit
V
Operating supply voltage 10.5 V
S
T
amb
T
Table 2. Thermal data
Symbol Parameter Value Unit
Operating ambient temperature -40 to 85 °C
Storage temperature range -55 to 150 °C
stg
R
th j-amb
Table 3. Quick reference data
Thermal resistance junction-pins 150 °C/W
Symbol Parameter Min. Typ. Max. Unit
Supply voltage 6 9 10.2 V
V
S
V
Max. input signal handling 2.1 2.6 Vrms
CL
THD Total harmonic distortion V = 1Vrms f = 1KHz 0.01 0.08 %
S/N Signal to noise ratio 106 dB
Channel separation 100 dB
S
C
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
Table 4. Electrical characteristics
(V
= 9V; RL = 10KΩ; Rg = 50Ω; T
S
= 25°C; all gains = 0dB; f = 1KHz. Refer
amb
to the test circuit, unless otherwise specified.)
Symbol Parameter Test condition Min. Typ. Max. Unit
Input selector
R
Input resistance 70 100 130 KΩ
I
Clipping level d ≤ 0.3% 2.1 2.6 V
V
CL
S
Input separation 80 100 dB
I
Output load resistance 2 KΩ
R
L
Minimum input gain -0.75 0 0.75 dB
G
I MIN
G
Maximum input gain 10.25 11.25 12.25 dB
I MAX
6/20
RMS
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