Principle of operation

TDA7576B

12/17

Doc ID 023511 Rev 3

load resistance (supposed identical for the two speakers).

In the common practice the two channels of the amplifier are used for the left and the right

audio parts of the stereo signal, and therefore the two outputs are not identical. This means

that it is never mathematically true that all the current into one speaker comes from the other

speaker, so the HVcc buffer will always have to provide a certain amount of difference

current.

Apart from the fact that the left and the right audio channels are not identical unless the

program is monophonic, other reasons why the HVcc buffer has to provide current are:

imbalance in the level of the L and the R channel, equalization-induced delay in one channel

compared to the other.

The current provided by the HVCC buffer leads to non-negligible power dissipation inside

the IC: this should be added to power dissipation the output stages 1 and 2. It is necessary

to keep this additional dissipation in mind when dimensioning the car-radio heat sink.