TDA7370B Datasheet, PDF (13/17 Pages) STMicroelectronics – QUAD POWER AMPLIFIER FOR CAR RADIO

TDA7370B
CLIPPING DETECTOR
Figures 25 and 26 show an application using the
TDA7370B in combination with the SGS-THOM-
SON audioprocessor TDA7302.
The output clipping is recognized by the microproc-
essor (in this application it is simulated by a PC).
The detailed way to operate of the system is rep-
resented by the flow-chart of fig.24
The controller detects when the clipping is active
(minimun detection width fixed by a C29 = 12 nF
external capacitor), and reduces the volume (or
bass ) by steps of 2 dB (with a programmable
waiting time), until no more clipping is detected.
Then the controller waits for a programmable time
before increasing the volume again by step of 2
dB until clipping is again detected or the panel se-
lected volume is reached.
Practical advantages of this application is a better
sound quality deriving from operation under no
clipping conditions, which also means the avail-
ability of higher undistorted power.
Figure 24: Clipping Detector Control Routine
WHAT IS NEEDED FOR A DEMONSTRATION
- a XT or AT IBM compatible PC, supplied with
EGA card
- a SGS-THOMSON audioprocessor application disk
- a TDA 7302 + TDA7370B board
- a connector from audioprocessor board to PC
parallel port
GENERAL INFORMATION
In the application shown in figures 25 and 26 the
TDA7302 audioprocessor works on PC XT or AT
IBM compatible.
Control is accomplished by serial bus ( S-bus or
I²C-bus or SPI bus) sent to the test board through
the PC parallel port.
The PC simulates the behaviour of the microproc-
essor in a real application (for example in a car
radio) and the buffer is necessary only in this ap-
plication for protecting the PC.
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