TDA7335
STEREO PREAMP + AMS + DOLBY B*
NOISE REDUCTION PROCESSOR
DUAL CHANNEL PROCESSOR FOR PLAY-
BACK APPLICATIONS.
STEREO DOLBY B NR SYSTEM
LOW NOISE HEAD PREAMPLIFIER
MUTE, AUTOREVERSE, AMS (AUDIO MU-
SIC SENSOR) FUNCTIONS
INTERNAL SWITCHES FOR EQUALIZATION
DOLBY
REFERENCE
LEVEL
-6dBm
(388.2mV
RMS
)
MINIMUM NUMBER OF EXTERNAL COMPO-
NENTS
LOW SUPPLY CURRENT (18mA)
MIXED BIPOLAR/CMOS TECHNOLOGY
DESCRIPTION
The TDA7335 is a monolithic BICmos IC de-
signed for use in stereo cassette player systems.
The device includes two separate audio channels
composed by low noise preamplifier, Dolby B
noise reduction system and Audio Music Sensor.
The dual preamplifier contains mute, autoreverse,
metal/normal facilities for amplification of low level
signal in applications requiring very low noise per-
formances.
Each channel consists of two cascaded opera-
tional amplifiers.
The first one, AMP1, has a fixed gain of 36dB,
low noise forward/reverse switchable input, and
allows magnetic heads connection directly to
ground. The second one, AMP2, is a standard op-
erational amplifier whose equalizing external
components fix the frequency response.
The Audio Music Sensor circuit detects the inter-
program space and then the starting point of mu-
sical programs (the interprogram time and pro-
gram detection time are externally selectable).
The device contains Dolby B decoder NR chains
requiring very few external components and do
not require coils.
* Dolby B and the Double-D symbol are
trademarks of Dolby Laboratories Li-
censing Corporation, San Francisco,
California 94103-4813, USA.
This device is available only to Licens-
ing and application information may be
obtained from Dolby Lab.
November 1999
PIN CONNECTION (Top view)
SDIP30
ORDERING NUMBER: TDA7335
1/20
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
S
Supply Voltage
12
V
P
tot
Total Power Dissipation
1
W
T
op
Operating Temperature Range
-40 to 85
C
T
stg
Storage Temperature Range
-40 to 150
C
THERMAL DATA
R
th j-pins
Thermal resistance junction-pins
85
C/W
PIN FUNCTIONS
N.
Name
V
DC
(V)
Function
1
GND
Ground
2,3
IN L
1
, IN L
2
0
Preamplifier Left Inputs 1,2
4,27
EQLI, EQRI
4.6
Equalizer Inputs
5, 26
EQLO, EQRO
4.6
Equalizer Outputs
6, 25
OUTL, OUTR
4.6
Preamplifier Outputs
7, 24
DINL, DINR
V
ref
Dolby NR Inputs
8
AMS SW
5.6
Audio Music Sensor Switch (ON/OFF) HIGH = ON
9
INTP
Interprogram Time Constant ("Signal Detection")
10
INTS
Interspace Time Constant ("Blank Detection")
11
MUTE
Mute Switch ON = LOW (2)
12, 19
TLC, TCR
0.4
Dolby Time Constants
13, 18
DOUTL, DOUTR
V
ref
Dolby Outputs
14
I
ref
1.2
Reference Current Source
15
F/R SW
5.6
Forward/Reverse Switch HIGH = Forward LOW = Reverse
16
V
S
Positive Power Supply
17
V
ref
V
S
/2
Reference Voltage
20
NR SW
Noise reduction ON/OFF: HIGH = OFF (2)
21
AMS GIN
1.4
Audio Music Sensor Input Pin
22
AMS OUT
Audio Music Sensor Output Pin (open collector configuration, see Fig. 2)
23
GND DIG.
0
Digital Ground
28, 29
IN R
1
, IN R
2
0
Preamplifier Right Inputs 1,2
30
EQ SW
0
Equalizer Switch (Low = normal position High = metal position)
(2) Internal pull-up resistor (digital high level if pin left open)
TDA7335
2/20
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