signed in order to obtain a virtually pop-free tran-

sition has to be slower than 2.5V/ms.

CLIPPING DETECTOR

The CLIPPING DETECTOR acts in a way to out-

put a signal as soon as one or more outputs

reach or trespass a typical THD level of 10%.

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

takes the form of pulses, which are syncronized

with each single clipping event in the music pro-

gram.

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-

tor has to be viewed mainly as a power-depend-

ent feature rather than frequency-dependent.This

means that clipping state causing THD = 10%

typ. will be immediately signaled out whenever a

fixed power level is reached, regardless of

the

audio frequency.

In other words, this feature offers the means to

counteract the extremely sound-damaging effects

of heavy clipping, caused by a sudden increase of

odd order harmonics and appearance of serious

intermodulation phenomena.

VREF

R

Vpin 25

25

D97AU810

TDA7382

Figure 12: Diagnostics circuit.

AUDIO

OUTPUT

SIGNAL

CLIPPING

DET.

OUTPUT

CURR.

time

D97AU811

ICLIP

0

Figure 13: Clipping Detection Waveforms.

t

t

t

MUTE PIN

VOLTAGE

Vs

OUTPUT

WAVEFORM

Vpin 25

WAVEFORM

D97AU812A

CLIPPING

ST-BY PIN

VOLTAGE

t

Figure 14: Diagnostics Waveforms.

TDA7382

8/10