5 General structure

STA543SA

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CD00061065

Figure 12. Fault waveforms

5.8

Handling of the diagnostic information

As different kinds of information is available at the same pin (clipping detection, output fault,

thermal proximity), this signal must be handled properly in order to discriminate the event.

This could be done taking into account the different timing of the diagnostic output during each

case.

Normally the clip detector signalling produces a

low level at out 12 that present under faulty conditions: based on this assumption an interface

circuitry to differentiate the information is the represented in the schematic of

Figure 14.

Figure 13. Waveforms

SOFT SHORT

OUT TO Vs SHORT

FAULT DETECTION

CORRECT TURN-ON

OUT TO GND SHORT

t

t

t

ST-BY PIN

VOLTAGE

2V

OUTPUT

WAVEFORM

Vpin 12

CHECK AT TURN-ON

(TEST PHASE)

SHORT TO GND

OR TO Vs

D05AU1603

t

t

t

ST-BY PIN

VOLTAGE

Vs

OUTPUT

WAVEFORM

Vpin 12

WAVEFORM

SHORT TO GND

OR TO Vs

D05AU1604

CLIPPING

THERMAL

PROXIMITY