TDA7381 STMicroelectronics, TDA7381 Datasheet - Page 8

• Manufacturer Part Number: TDA7381
• Description: IC AMP AUDIO PWR 30W 25FLEXIWATT
• Manufacturer: STMicroelectronics
• Type: Class ABr

Specifications of TDA7381

• Output Type: 4-Channel (Quad)
• Max Output Power X Channels @ Load: 30W x 4 @ 4 Ohm
• Voltage - Supply: 8 V ~ 18 V
• Features: Mute, Short-Circuit and Thermal Protection, Standby
• Mounting Type: Through Hole
• Package / Case: 25-Flexiwatt (bent and staggered leads)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application hints
3.4
8/13
Diagnostics facility
The TDA7381 is equipped with a diagnostics circuitry able to detect the following events:
●
●
●
Diagnostics information is available across an open collector output located at pin 25 (fig. 8)
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
syncronized with each single clipping event in the music program and reflect the same
duration time
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
association with microprocessor-driven audioprocessors.
The maximum load that pin 25 can sustain is 1 kΩ. Due to its operating principles, the
clipping detector has to be viewed mainly as a power-dependent feature rather than
frequency-dependent. This means that clipping state will be immediately signaled out
whenever a fixed power level is reached, regardless of the audio frequency.
Figure 6.
Figure 7.
Clipping in the output stage
Overheating (thermal shut-down proximity)
Output misconnections (OUT-GND and OUT-Vs shorts)
Input/output biasing.
Diagnostics circuit
(Figure
V
S
10KΩ
10KΩ
8).
70KΩ
SVR
TDA7385
C1 ÷ C4
0.1μF
47μF
100KΩ
100KΩ
C6
IN
AC_GND
0.1μF
25
C5
Vpin 25
D95AU302
400Ω
400Ω
D95AU303
R
+
+
-
-
8KΩ
8KΩ
VREF
OTHER CHANNELS
TOWARDS
TDA7381