TDA7383 Datasheet, PDF (7/12 Pages) STMicroelectronics – 4 x 30W QUAD BRIDGE CAR RADIO AMPLIFIER

TDA7383
Figure 9: Output Noise vs. Source Resistance
En (µV)
200
180
160
Vs= 14.4 V
RL= 4 Ohm
140
120
100
80
22 - 22K Hz lin.
”A” wgtd
60
40
1
10
100
1k
Rg (Ohm)
10k 100k
Figure 10: Power Dissipation & Efficiency vs.
Output Power
Ptot (W)
APPLICATION HINTS (ref. to the circuit of fig. 1)
BIASING AND SVR
As shown by fig. 11, all the TDA7383’s main sec-
tions, such as INPUTS, OUTPUTS AND AC-GND
(pin 16) are internally biased at half Supply Volt-
age level (Vs/2), which is derived from the Supply
Voltage Rejection (SVR) block. In this way no cur-
rent flows through the internal feedback network.
The AC-GND is common to all the 4 amplifiers
and represents the connection point of all the in-
verting inputs.
Both individual inputs and AC-GND are con-
nected to Vs/2 (SVR) by means of 100KΩ resis-
tors.
To ensure proper operation and high supply volt-
age rejection, it is of fundamental importance to
provide a good impedance matching between IN-
PUTS and AC-GROUND terminations. This im-
plies that C1, C2, C3, C4, C5 CAPACITORS HAVE
TO CARRY THE SAME NOMINAL VALUE AND
THEIR TOLERANCE SHOULD NEVER EXCEED
±10 %.
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.
Figure 11: Input/OutputBiasing.
100KΩ
0.1µF
C1 ÷ C4
IN
+
-
8KΩ
400Ω
V_S
10KΩ
70KΩ _SVR
10KΩ
100KΩ
47µF
C6
400Ω
8KΩ
-
AC_GND ₊
0.1µF
C5
D95AU302
TOWARDS
OTHER CHANNELS
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