TDA7384A Datasheet, PDF (7/9 Pages) STMicroelectronics – 4 x 35W QUAD BRIDGE CAR RADIO AMPLIFIER

Figure 9: Output Noise vs. Source Resistance
TDA7384A
Figure 10: Power Dissipation & Efficiency vs.
Output Power
APPLICATION HINTS (ref. to the circuit of fig. 1)
SVR
Besides its contribution to the ripple rejection, the
SVR capacitor governs the turn ON/OFF time se-
quence and, consequently, plays an essential role
in the pop optimization during ON/OFF transients.
To conveniently serve both needs, ITS MINIMUM
RECOMMENDED VALUE IS 10µF.
INPUT STAGE
The TDA7384A’S inputs are ground-compatible
and can stand very high input signals (± 8Vpk)
without any performances degradation.
If the standard value for the input capacitors
(0.1µF) is adopted, the low frequency cut-off will
amount to 16 Hz.
STAND-BY AND MUTING
STAND-BY and MUTING facilities are both
CMOS-COMPATIBLE. If unused, a straight con-
nection to Vs of their respective pins would be ad-
missible. Conventional/low-power transistors can
be employed to drive muting and stand-by pins in
absence of true CMOS ports or microprocessors.
R-C cells have always to be used in order to
smooth down the transitions for preventing any
audible transient noises.
Since a DC current of about 10 uA normally flows
out of pin 22, the maximum allowable muting-se-
ries resistance (R2) is 70KΩ, which is sufficiently
high to permit a muting capacitor reasonably
small (about 1µF).
If R₂ is higher than recommended, the involved
risk will be that the voltage at pin 22 may rise to
above the 1.5 V threshold voltage and the device
will consequently fail to turn OFF when the mute
line is brought down.
About the stand-by, the time constant to be as-
signed in order to obtain a virtually pop-free tran-
sition has to be slower than 2.5V/ms.
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