DIGITALLY CONTROLLED AUDIO PROCESSOR
INPUTMULTIPLEXER
- THREE STEREOAND ONE MONOINPUTS
- SELECTABLEINPUT GAIN FOR OPTIMAL
ADAPTATIONTO DIFFERENTSOURCES
VOLUME CONTROL IN 0.3dB STEPS INCLUDINGGAIN UP TO 20dB
ZERO CROSSING MUTE AND DIRECT
MUTE
PAUSEDETECTOR WITH PROGRAMMABLE
THRESHOLD
SOFT MUTE CONTROLLED BY SOFTWARE
OR HARDWAREPIN
BASS AND TREBLE CONTROL
FOURSPEAKER ATTENUATORS
- FOUR INDEPENDENTSPEAKERS
CONTROLIN 1.25dBSTEPSFOR
BALANCEAND FADER FACILITIES
- INDEPENDENT MUTEFUNCTION
ALL FUNCTIONS PROGRAMMABLE VIA SE-
2
RIAL I
DESCRIPTION
The TDA7348 is an upgrade of the TDA7318
audioprocessor.
Thanks to the used BIPOLAR/CMOStechnology,
very low distortion, low noise and DC-stepping
are obtained.
CBUS
TDA7348
PRODUCT PREVIEW
DIP28 SO28
ORDERING NUMBER: TDA7348 (DIP28)
TDA7348D (SO28)
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, zero-crossing mute and pause detector
areimplemented.
The Soft Mute function can be activated in two
ways:
1 Via serial bus (bit D0, Mute Byte)
2 Directly on pin 22 through an I/O line of the
microcontroller
Very low DC stepping is obtained by use of a
BICMOStechnology.
November 1994
This is advanced information on a new product now in developmentor undergoing evaluation. Details are subject to change without notice.
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TDA7348
BLOCK DIAGRAM
BUSSERIAL BUS DECODER + LATCHES
R2
4.7K
C16
C15
C14
2.7nF
TREBLE(L)
100nF
100nF
BOUT(L) BIN(L)
SM
4
19 18
22
ATT
SPKR
RB
26
OUT
LEFT FRONT
MUTE
SPKR
TREBLE
BASS
1, 2
VOL
ATT
24
OUT
LEFT REAR
MUTE
28
SCL
27
SOFT
SDA
MUTE
ATT
SPKR
25
OUT
RIGHT FRONT
MUTE
TREBLE
BASS
VOL
OUT
RIGHT REAR
23
D93AU100A
ATT
SPKR
1, 2
RB
MUTE
TREBLE(R)
BOUT(R) BIN(R)
21 20 5
15
CSM
C13
C12
C11
CSM
2.7nF
100nF
R1
47nF
4.7K
2/14
ZERO
ZERO
MUTE
CROSS +
C10 2.2µF
17 16
OUT(L) IN(L)
INPUT
+ GAIN
SELECTOR
L1
L2
14
13
L1
L2
3x
1µF
C1
LEFT
12 L3
L3
C2
INPUTS
L4
11
C4
C3
R4
3x
MUTE
CROSS +
R1
R2
10R1
9
R3 R38
R2
1µF
C7
C6
C5
RIGHT
INPUTS
6
7
OUT(R)CREF IN(R)
10µF
C8
SUPPLY
31
2
AGND
S
V
C9 2.2µF
ABSOLUTE MAXIMUMRATINGS
Symbol Parameter Value Unit
V
S
T
amb
T
stg
Operating Supply Voltage 10.5 V
Operating Ambient Temperature -40 to 85 °C
Storage Temperature Range -55 to 150 °C
PIN CONNECTION
TDA7348
TREBLE
CREF
V
GND
IN(R)
OUT(R)
IN R3
IN R2
IN R1
AM MONO
IN L3
IN L2
IN L1
1
2
S
3
4
L
5
R OUT LR
6
7
8
9
10
11
12
13
14
D94AU099
28
27
26
25
24
22
21
20
19
18
17
16
15
SCL
SDA
OUT LF
OUT RF
OUT RR23
SM
BOUT(R)
BIN(R)
BOUT(L)
BIN(L)
OUT(L)
IN(L)
CSM
BUS
INPUTS
BASS
THERMAL DATA
Symbol Parameter DIP28 SO28 Unit
R
th j-amb
Thermal Resistance Junction-pins 85 65 °C/W
QUICK REFERENCE DATA
Symbol Parameter Min. Typ. Max. Unit
V
S
V
CL
THD Total Harmonic Distortion V = 1Vrms f = 1KHz 0.01 0.08 %
S/N Signal to Noise Ratio 106 dB
S
C
Supply Voltage 6 9 10.2 V
Max. inputsignal handling 2.1 2.6 Vrms
Channel Separation f = 1KHz 100 dB
Volume Control -78.45 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
3/14
TDA7348
ELECTRICALCHARACTERISTICS (VS= 9V; RL=10KΩ;Rg=50Ω;T
=25°C; all controls flat
amb
(G = 0.3dB step 0dB); f = 1KHz. Refer to the test circuit,unless otherwise specified.)
Symbol Parameter Test Condition Min. Typ. Max. Unit
INPUT SELECTOR
G
G
R
V
S
R
I MIN
I MAX
G
e
V
I
CL
I
L
step
N
DC
Input Resistance 70 100 130 KΩ
Clipping Level d ≤ 0.3% 2.1 2.6 V
Input Separation 80 100 dB
Output Load Resistance 2 KΩ
Minimum Input Gain -0.75 0 0.75 dB
Maximum Input Gain 10.25 11.25 12.25 dB
Step Resolution 2.75 3.75 4.75 dB
Input Noise 20Hz to 20 KHz unweighted 2.3 µV
DC Steps Adiacent Gain Steps 1.5 10 mV
to G
G
IMIN
IMAX
3mV
VOLUMECONTROL(1 + 2)
R
I
G
MAX
A
MAX
A
STEPC
A
STEPF
E
A
E
t
V
DC
Input Resistance 35 50 KΩ
Maximum Gain 18.75 20 21.25 dB
Maximum Attenuation 78.45 dB
Step Resolution Coarse
0.5 1.25 2.0 dB
Attenuation
StepResolution Fine Attenuation (Only Volume 1) 0.11 0.31 0.51 dB
Attenuation Set Error G = 20 to -20dB -1.25 0 1.25 dB
G = -20 to -58dB -3 2 dB
Tracking Error 2dB
DC Steps Adiacent Attenuation Steps -3 0 3 mV
From 0dB to A
MAX
0.5 5 mV
ZEROCROSSING MUTE
A
V
TH
MUTE
V
DC
Zero Crossing Threshold
(note 1)
WIN = 11 20 mV
WIN = 10 40 mV
WIN = 01 80 mV
WIN = 00 160 mV
Mute Attenuation 80 100 dB
DC Step 0dB to Mute 0 3 mV
RMS
SOFT MUTE
A
MUTE
T
DON
T
DOFF
V
THSM
R
INT
V
SMH
V
SML
4/14
Mute Attenuation 45 60 dB
ON Delay Time CCSM = 22nF; 0 to -20dB;I = IMAX 0.7 1 1.7 ms
CSM =22nF; 0 to -20dB; I = IMIN 20 35 55 ms
C
OFF Current VCSM =0V;I=IMAX 25 50 75 µA
CSM = 0V;I =IMIN 1 µA
V
Soft Mute Threshold 1.5 2.5 3.5 V
Pullup Resistor (pin 22) (note 2) 35 50 65 KΩ
(pin 22) Level High Soft Mute Active 3.5 V
(pin 22) Level Low 1V
TDA7348
ELECTRICALCHARACTERISTICS (continued)
Symbol Parameter Test Condition Min. Typ. Max. Unit
BASSCONTROL
B
BOOST
B
CUT
A
step
R
g
TREBLE CONTROL
C
RANGE
A
step
SPEAKERATTENUATORS
C
RANGE
A
step
A
MUTE
E
A
V
DC
AUDIO OUTPUT
V
clip
R
L
R
O
V
DC
GENERAL
V
CC
I
CC
PSRR Power SupplyRejection Ratio f = 1KHz 60 80 dB
e
NO
E
t
S/N Signal to Noise Ratio All Gains = 0dB; V
S
C
d Distortion V
Max Bass Boost 15 18 20 dB
Max Bass Cut -8.5 -10 -11.5 dB
Step Resolution 1 2 3 dB
Internal Feedback Resistance 45 65 85 KΩ
Control Range ±13 ±14 ±15 dB
Step Resolution 1 2 3 dB
Control Range 35 37.5 40 dB
Step Resolution 0.5 1.25 2.0 dB
Output Mute Attenuation Data Word = XXX11111 80 100 dB
Attenuation Set Error 1.25 dB
DC Steps Adjacent Attenuation Steps 0 3 mV
Clipping Level d = 0.3% 2.1 2.6 Vrms
Output Load Resistance 2 KΩ
Output Impedance 30 100 Ω
DC Voltage Level 3.5 3.8 4.1 V
Supply Voltage 6 9 10.2 V
Supply Current 10 15 mA
B = 20 to 20kHz ”A” weighted 65 dB
Output Noise OutputMuted(B=20to20kHzflat) 2.5 µV
All Gains 0dB (B = 20 to20kHz flat) 5 15 µV
Total Tracking Error AV = 0 to -20dB 0 1 dB
= -20 to -60dB 0 2 dB
A
V
O
=1V
rms
106 dB
Channel Separation 80 100 dB
= 1V 0.01 0.08 %
IN
BUS INPUTS
V
IL
V
lN
I
lN
V
O
Note 1: WIN represents the MUTE programming bit pair D6,D5for the zero crossing window threshold
Note 2: Internal pullup resistor to Vs/2; ”LOW” = softmute active
r
Input Low Voltage 1V
Input High Voltage 3 V
Input Current VIN = 0.4V -5 5 µA
Output Voltage SDA
IO= 1.6mA 0.4 0.8 V
Acknowledge
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