TDA7575PD

12/17

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.

Fig A: Turn - On diagnostic: working principle

Fig. B and C show SVR and OUTPUT waveforms at the turn-on (stand-by out) with and without TURN-ON DI-

AGNOSTIC.

Fig B: SVR and Output behaviour

CASE 1: without turn-on diagnostic

FIG. C: SVR and Output pin behaviour

CASE 2: with turn-on diagnostic

CH-

CH+

Isource

Vs~5V

Isink

t (ms)

I (mA)

Isink

Isource

~100mS

Measure time

Bias (power amp turn-on)

t

Diagnostic Enable

(Permanent)

Permanent diagnostic

acquisition time (100mS Typ)

Permanent Diagnostics data (output)

permitted time

I2CB DATA

Vsvr

Out

FAULT

event

Read Data

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