TDA7350A Datasheet, PDF (9/22 Pages) STMicroelectronics – 22W BRIDGE-STEREO AMPLIFIER FOR CAR RADIO

Figure 21: Power Dissipation & Efficiency vs.
Output Power (Stereo)
Figure 22: Power Dissipation & Efficiency vs.
Output Power (Bridge)
TDA7350A
saving due to the minimized external count, ex-
cellent electrical performances, flexibility in use,
superior reliability thanks to a built-in array of pro-
tections. As a result the following performances
has been achieved:
NO NEED OF BOOTSTRAP CAPACITORS
EVEN AT THE HIGHEST OUTPUT POWER
LEVELS
ABSOLUTE STABILITY WITHOUT EXTER-
NAL COMPENSATION THANKS TO THE IN-
NOVATIVE OUT STAGE CONFIGURATION,
ALSO ALLOWING INTERNALLY FIXED
CLOSED LOOP LOWER THAN COMPETI-
TORS
LOW GAIN (30dB STEREO FIXED WITHOUT
ANY EXTERNAL COMPONENTS) IN ORDER
TO MINIMIZE THE OUTPUT NOISE AND OP-
TIMIZE SVR
SILENT MUTE/ST-BY FUNCTION FEATUR-
ING ABSENCE OF POP ON/OFF NOISE
HIGH SVR
STEREO/BRIDGE OPERATION WITHOUT
ADDITION OF EXTERNAL COMPONENT
AC/DC SHORT CIRCUIT PROTECTION (TO
GND, TO V_S, ACROSS THE LOAD)
LOUDSPEAKER PROTECTION
DUMP PROTECTION
ESD PROTECTION
Figure 23: Power Dissipation & Efficiency vs.
Output Power (Bridge)
BLOCK DESCRIPTION
Polarization
The device is organized with the gain resistors di-
rectly connected to the signal ground pin i.e. with-
out gain capacitors (fig. 24).
The non inverting inputs of the amplifiers are con-
nected to the SVR pin by means of resistor divid-
ers, equal to the feedback networks. This allows
the outputs to track the SVR pin which is suffi-
ciently slow to avoid audible turn-on and turn-off
transients.
SVR
The voltage ripple on the outputs is equal to the
one on SVR pin: with appropriate selection of
CSVR, more than 55dB of ripple rejection can be
obtained.
AMPLIFIER ORGANIZATION
The TDA7350A has been developed taking care
of the key concepts of the modern power audio
amplifier for car radio such as: space and costs
Delayed Turn-on (muting)
The C_SVR sets a signal turn-on delay too. A circuit
is included which mutes the device until the volt-
age on SVR pin reaches ~2.5V typ (fig. 25). The
mute function is obtained by duplicating the input
differential pair (fig. 26): it can be switched to the
signal source or to an internal mute input. This
feature is necessary to prevent transients at the
inputs reaching the loudspeaker(s) immediately
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