TDA7360 datasheet(19/22 Pages) STMICROELECTRONICS

19 / 22 page

BALANCED INPUT IN BRIDGE CONFIGURATION

A helpful characteristic of the TDA7360 is that,in

bridge configuration, a signal present on both the

input capacitors is amplified by the same amount

and it is present in phase at the outputs,so this

signal does not produce effects on the load.The

typical value of CMRR is 46 dB.

Looking at fig 46, we can see that a noise signal

from the ground of the power amplifier to the

ground of the hypothetical preamplifier is ampli-

fied of a factor equal to the gain of the amplifier

(2 * Gv).

Using a configuration of fig. 47 the same ground

noise is present at the output multiplied by the

factor 2 * Gv/200.

This means less distortion,less noise (e.g. motor

cassette noise ) and/or a simplification of the lay-

out of PC board.

The only limitation of this balanced input is the

maximum amplitude of common mode signals

(few tens of millivolt) to avoid a loss of output

power due to the common mode signal on the

output, but in a large number of cases this signal

is within this range.

Figure 46

Figure 47

Figure 45

TDA7360

19/22

TDA7360 Datasheet(PDF) 19 Page - STMicroelectronics