TDA7340G STMicroelectronics, TDA7340G Datasheet - Page 19

• Manufacturer Part Number: TDA7340G
• Description: IC PROCESSOR AUDIO SIGNAL 44PQFP
• Manufacturer: STMicroelectronics
• Type: Car Signal Processorr

Specifications of TDA7340G

• Applications: Automotive
• Mounting Type: Surface Mount
• Package / Case: 44-MQFP, 44-PQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 6: Behaviour of the Field Strength Controlled Threshold Adjustment
Figure 7: Behaviour of the Deviation Dependent Threshold Adiust (Over Deviation Detector)
MUTE & PAUSE FEATURES
The TDA7340G provides three types of mute,
controlled via I2C bus (see pag.12, MUTE BYTE
register).
SOFT MUTE
Bit D0=1
Bit D0=0
It allows an automatic soft muting and unmuting
of the signal.
The time constant is fixed by an external capaci-
tor Csm inserted between pin Csm and ground.
Once fixed the external capacitor, two different
slopes (time constant) are selectable by program-
mation of bit D1.
Soft Mute OFF
Soft Mute ON
V PEAK
V PEAK
(V)
D95AU332A
3V
3.2
2.3
1.3
0.9
TRIG. THRESHOLD
NOISE
noisy signal
20
32.5
MONO
D95AU333A
45
ATC_SB OFF (11)
Bit D1=1
Bit D1=0
The soft mute generates a gradual signal de-
creasing avoiding big click noise of an immediate
high attenuation, without necessity to program a
sequence of decreasing volume levels. A re-
sponse example is reported in Fig.12 (mute) and
Fig.13 (unmute). The final attenuation obtained
with soft mute ON is 60dB typical.
The used reference parameter is the delay time
taken to reach 20dB attenuation (no matter what
the signal level is).
Using a capacitor Csm=22nF this delay is:
d = 1. 8ms when selected Fast slope mode (bit D1=1)
d = 25 ms when selected Slow slope mode (bit D1=0)
75
STEREO
good signal
DETECTOR OFF (11)
fast slope (I=Imax)
slow slope (I=Imin)
2.2V(00)
1.8V(01)
1.2V(10)
OVM =00
DEVIATION(KHz)
OVM =01
OVM =10
E'
0.9V
TDA7340G
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