STA540

Practical information

19/23

6.8

Handling the diagnostic information

As different diagnostic information (clipping detection, output fault, approaching thermal

shutdown) becomes available at pin 10 so the behavior of the signal at this pin changes.

In order to discriminate the event, signal DIAGNOSTICD, pin 10, must be interpreted

correctly. Figure 27 shows a combination of events on the output waveform and the

corresponding output on pin 10.

This events could be diagnosed based on the timing of the output signal on pin 10. For

example, the clip-detector signalling under fault conditions could produce a low level for a

short time. On the other hand, an output short circuit would probably produce a low level for

a much longer time. With these assumptions, an interface circuit based on the one shown in

Figure 28 could differentiate the information and flag the appropriate circuits.

Figure 27.

Waveforms

Figure 28.

Interface circuit diagram

t

t

t

ST-BY PIN

VOLTAGE

Vs

OUTPUT

WAVEFORM

Vpin 10

WAVEFORM

SHORT TO GND

OR TO Vs

D05AU1604mod

CLIPPING

THERMAL

PROXIMITY