TDA7563 Datasheet, PDF (8/20 Pages) STMicroelectronics – MULTIFUNCTION QUAD POWER AMPLIFIER WITH BUILT-IN DIAGNOSTICS FEATURES

TDA7563
Figure 14. Power Dissipation vs. Average
Ouput Power (Audio Program
Simulation, 4Ω)
Ptot (W)
45
40
Vs = 14 V
35 RL = 4 x 4 Ohm
GAUSSIAN NOISE
30
25
20
STD MODE
CLIP
START
HI-EFF MODE
15
10
5
0
0
1
2
3
4
5
Po (W)
Figure 15. Power Dissipation vs. Average
Ouput Power (Audio Program
Simulation, 2Ω)
Ptot (W)
90
80
70
Vs = 14 V
60
RL = 4 x 2 Ohm
GAUSSIAN NOISE
50
40
STD MODE
CLIP
START
30
HI-EFF MODE
20
10
0
0
1
2
3
4
5
6
7
8
9
Po (W)
DIAGNOSTICS FUNCTIONAL DESCRIPTION:
a) TURN-ON DIAGNOSTIC
It is activated at the turn-on (stand-by out) under I²Cbus request. Detectable output faults are:
– SHORT TO GND
– SHORT TO Vs
– SHORT ACROSS THE SPEAKER
– OPEN SPEAKER
To verify if any of the above misconnections are in place, a subsonic (inaudible) current pulse (fig. 16) is inter-
nally generated, sent through the speaker(s) and sunk back.The Turn On diagnostic status is internally stored
until a successive diagnostic pulse is requested (after a I2C reading).
If the "stand-by out" and "diag. enable" commands are both given through a single programming step, the pulse
takes place first (power stage still in stand-by mode, low, outputs= high impedance).
Afterwards, when the Amplifier is biased, the PERMANENT diagnostic takes place. The previous Turn On state
is kept until a short appears at the outputs.
Figure 16. Turn - On diagnostic: working principle
Vs~5V
I (mA)
Isource
Isource
CH+
CH-
Isink
Isink
~100mS
Measure time
t (ms)
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