AN1643 Datasheet, PDF (1/7 Pages) STMicroelectronics – 6 CH VOLUME CONTROLLER

AN1643
APPLICATION NOTE
6 CH VOLUME CONTROLLER
PLUS SAM261 BASH AMPLIFIER
by Luigi Pagotto & Marco Motta
In this document is explained how to connect the Audio processor TDA7448 to the board BASH
SAM261, in order to obtain a complete amplifier with the volume controlled via I²C bus.
Before to start the description we summarize what are the characteristic of the two boards.
TDA7448 Board:
With this board is possible to obtain the independent Volume Control for six channels in 1.0dB Steps, the
Volume attenuation ranges from 0 to -79dB.
All functions are programmable via serial Bus (I²C).
The board is feed with a supply voltage ranging from 4.75 to10V.
It will be also described how to use the control sw.
SAM261 BOARD:
SAM261 is a BASH@6.1 (6x50W + 1X100W) amplifier utilizing the STA530 IC.
This board is specifically designed for multi-channel implementation in DVD - HTIB
Systems, Multi - Media systems, Mini and Micro systems and Set Top boxes.
SAM261 is dimensioned to provide the maximum Output Power (@ THD= 10%) on two channels and 1/3 max
Pout on the remaining Outputs, this assumption is important to define the main Power Supply size (+50V).
In this document we describe an application configuration where the used loads are:
5 X 50 W @ 8 ohm load (Left / Right/ Rear-Left /Rear- Right/ Centre)
1 X 100W @ 4 ohm load (Subwoofer)
CONTROL SOFTWARE
Figure 1.
January 2003
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