TDA7375AV

Functional description

Doc ID 6325 Rev 5

13/20

4

Functional description

4.1

High application flexibility

The availability of 4 independent channels makes it possible to accomplish several kinds of

applications ranging from 4 speakers stereo (F/R) to 2 speakers bridge solutions.

In case of working in single ended conditions the polarity of the speakers driven by the

inverting amplifier must be reversed respect to those driven by non inverting channels. This

is to avoid phase inconveniences causing sound alterations especially during the

reproduction of low frequencies.

4.2

Easy single ended to bridge transition

The change from single ended to bridge configurations is made simply by means of a short

circuit across the inputs, that is no need of further external components.

4.3

Gain internally fixed to 20 dB in single ended, 26 dB in bridge

Advantages of this design choice are in terms of:

●

components and space saving

●

output noise, supply voltage rejection and distortion optimization

4.4

Silent turn on/off and muting/standby function

The standby can be easily activated by means of a CMOS level applied to pin 7 through a

RC filter.

Under standby conditions the device is turned off completely (supply current = 1

A typ.;

output attenuation = 80 dB min.). Every ON/OFF operation is virtually pop free.

Furthermore, at turn-on the device stays in muting conditions for a time determined by the

value assigned to the SVR capacitor.

While in muting the device outputs become insensitive to any kind of signal that may be

present at the input terminals. In other words every transient coming from previous stages

doesn't produce unpleasant acoustic effects to the speakers.

4.5

Output stage

The fully complementary output stage was made possible by the development of a new

component: the ST exclusive power ICV PNP.

A novel design based upon the connection shown in Figure 22 has then allowed the full

exploitation of its possibilities. The clear advantages that this new approach has over

classical output stages are described below.