TDA7374

Output stage

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3.5

Clipping detector

Figure 23 shows an application using the TDA7374 in combination with the STM

audioprocessor TDA7302. The output clipping is recognized by the microprocessor (in this

application it is simulated by a PC). The detailed way to operate of the system is

represented by the flow-chart of Figure 22.

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 step 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 selected volume is reached.

Practical advantages of this application is a better sound quality deriving from operation

under no clipping conditions, which also means the availability of higher undistorted power.

Figure 22.

Clipping detector control routine

3.6

What is needed for a demonstration

●

IBM compatible PC with parallel port

●

STM audioprocessor application disk

●

TDA7302 + TDA7374 board

●

Connector from audioprocessor board to PC parallel port