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TDA7566

Figure 16. SVR and Output pin behaviour (CASE 2: with turn-on diagnostic)

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:

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:

If the Line-Driver mode (Gv= 12 dB and Line Driver Mode diagnostic = 1) is selected, the same thresholds will

change as follows:

Bias (power amp turn-on)

permitted time

Turn-on diagnostic

acquisition time (100mS Typ)

t

Read Data

Permanent diagnostic

acquisition time (100mS Typ)

Permanent Diagnostics data (output)

permitted time

Diagnostic Enable

(Turn-on)

Turn-on Diagnostics data (output)

permitted time

I2CB DATA

Vsvr

Out

Diagnostic Enable

(Permanent)

FAULT

event

D01AU1253

S.C. to GND

x

S.C. to Vs

0V

1.8V

x

Normal Operation

1.2V

S.C. across Load

x

Open Load

0V

1.5

Ω

70

Ω

Infinite

x

Normal Operation

0.5

Ω

130

Ω

D01AU1254

D01AU1252

S.C. across Load

x

Open Load

0

Ω

4.5

Ω

200

Ω

infinite

x

Normal Operation

1.5

Ω

400

Ω