TDA7566 Datasheet, PDF (9/19 Pages) STMicroelectronics – MULTIFUNCTION QUAD POWER AMPLIFIER WITH BUILT-IN DIAGNOSTICS FEATURES

Figure 16. SVR and Output pin behaviour (CASE 2: with turn-on diagnostic)
Vsvr
Out
Turn-on diagnostic
acquisition time (100mS Typ)
Permanent diagnostic
acquisition time (100mS Typ)
TDA7566
t
Diagnostic Enable
(Turn-on)
Turn-on Diagnostics data (output)
permitted time
Diagnostic Enable
(Permanent)
FAULT
event
Bias (power amp turn-on)
permitted time
Read Data
Permanent Diagnostics data (output)
permitted time
I2CB DATA
The information related to the outputs status is read and memorized at the end of the current pulse top. The
acquisition time is 100 ms (typ.). No audible noise is generated in the process. As for SHORT TO GND / Vs the
fault-detection thresholds remain unchanged from 26 dB to 12 dB gain setting. They are as follows:
S.C. to GND x Normal Operation x
S.C. to Vs
0V
1.2V 1.8V
V_S-1.8V V_S-1.2V
V_S
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Concerning SHORT ACROSS THE SPEAKER / OPEN SPEAKER, the threshold varies from 26 dB to 12 dB
gain setting, since different loads are expected (either normal speaker's impedance or high impedance). The
values in case of 26 dB gain are as follows:
S.C. across Load x Normal Operation x
Open Load
0V
0.5Ω 1.5Ω
70Ω
130Ω
Infinite
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If the Line-Driver mode (Gv= 12 dB and Line Driver Mode diagnostic = 1) is selected, the same thresholds will
change as follows:
S.C. across Load x Normal Operation x
Open Load
0Ω
1.5Ω 4.5Ω
200Ω 400Ω
infinite
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