My TDA7439 board


My sound controller board is finally finished. It’s based on the TDA9437 chip. The Dip version of this chip is only available in an annoying SDIP-30 package. It will not fit on a standard prototype board.

The board had inputs for 4 stereo sources (8 pins) and a single stereo output. The IC can select between any of the connected audio sources, and an appropriate gain can be set.
This board also allows a microcontroller to control volume, treble, mid-range and bass. Mute and independent speaker control functions are also available, but I dont think I will use them.

Data transmission from the microprocessor to the TDA7439 and vice versa takes place through the 2-wire I2C bus interface. This consists of the data and clock lines, SDA and SCL. Pull-up resistors to the positive supply voltage must be used (there are no internal pull-ups).

Power up

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