TDA7383 Datasheet, PDF (9/12 Pages) STMicroelectronics – 4 x 30W QUAD BRIDGE CAR RADIO AMPLIFIER

Figure 14: Diagnostics Waveforms.
ST-BY PIN
VOLTAGE
MUTE PIN
VOLTAGE
Vs
OUTPUT
WAVEFORM
TDA7383
t
t
t
Vpin 25
WAVEFORM
D95AU304
t
CLIPPING
SHORT TO GND THERMAL
OR TO Vs
PROXIMITY
reached.
As various kind of diagnostics information is avail-
able at pin 25 (CLIPPING, SHORTS AND OVER-
HEATING), it may be necessary to operate some
distinctions on order to treat each event sepa-
rately. This could be achieved by taking into ac-
count the intrinsically different timing of the diag-
nostics output under each circumstance.
In fact, clipping will produce pulses normally
much shorter than those present under faulty con-
ditions. An example of circuit able to distinguish
between the two occurrences is shown by fig. 15.
STABILITY AND LAYOUT CONSIDERATIONS
If properly layouted and hooked to standard car-
radio speakers, the TDA7383 will be intrinsically
stable with no need of external compensations
Figure 15.
VREF
25
T1
T2
T1 << T2
VREF ≥ VREF1 >> VREF2
-
+
VREF1
-
+
VREF2
CLIP DET. (TO GAIN
COMPRESSOR/
TONE CONTROL)
FAULT, THERMAL SHUTDOWN
(TO POWER SUPPLY
SECTION, µP VOLTAGE
REGULATOR, FLASHING SYSTEM)
D95AU305A
9/12