OUTPUT MISCONNECTIONS (OUT-GND &

OUT-Vs shorts)

Diagnostics information is available across an

open collector output located at pin 25 (fig. 4)

through a current sinking whenever at least one

of the above events is recognized.

Among them, the CLIPPING DETECTOR acts in

a way to output a signal as soon as one or more

power transistors start being saturated.

As a result, the clipping-related signal at pin 25

takes the form of pulses, which are perfectly syn-

cronized with each single clipping event in the

music program and reflect the same duration time

(fig. 5).

Applications making use of this facility

usually operate a filtering/integration of the pulses

train through passive R-C networks and realize a

volume (or tone bass) stepping down in associa-

tion with microprocessor-driven audioprocessors.

The maximum load that pin 25 can sustain is

1K

Ω.

Due to its operating principles, the clipping detec-

VREF

R

Vpin 25

25

D95AU303

TDA7385

Figure 4: Diagnostics circuit.

Figure 5: Clipping Detection Waveforms.

TDA7381

t

t

t

MUTE PIN

VOLTAGE

Vs

OUTPUT

WAVEFORM

Vpin 25

WAVEFORM

SHORT TO GND

OR TO Vs

D95AU304

CLIPPING

THERMAL

PROXIMITY

ST-BY PIN

VOLTAGE

t

Figure 6: Diagnostics Waveforms.

TDA7381

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