TDA7294S Datasheet, PDF (7/13 Pages) STMicroelectronics – 100V - 100W DMOS AUDIO AMPLIFIER WITH MUTE/ST-BY

Figure 4: Turn ON/OFF Suggested Sequence
+Vs
(V)
+40
TDA7294S
-40
-Vs
VIN
(mV)
VST-BY
PIN #9
5V
(V)
VMUTE
5V
PIN #10
(V)
IQ
(mA)
VOUT
(V)
OFF
ST-BY
MUTE
PLAY
In addition to the overload protection described
above, the device features a thermal shutdown
circuit which initially puts the device into a muting
state (@ Tj = 150 ^oC) and then into stand-by (@
Tj = 160 ^oC).
Full protection against electrostatic discharges on
every pin is included.
Figure 5: Single Signal ST-BY/MUTE Control
Circuit
MUTE/
ST-BY
MUTE STBY
20K
10K
30K
1N4148
10µF
10µF
D93AU014
3) Other Features
The device is provided with both stand-by and
ST-BY
OFF
MUTE
D98AU817
mute functions, independently driven by two
CMOS logic compatible input pins.
The circuits dedicated to the switching on and off
of the amplifier have been carefully optimized to
avoid any kind of uncontrolled audible transient at
the output.
The sequence that we recommend during the
ON/OFF transients is shown by Figure 4.
The application of figure 5 shows the possibility of
using only one command for both st-by and mute
functions. On both the pins, the maximum appli-
cable range corresponds to the operating supply
voltage.
APPLICATION INFORMATION
HIGH-EFFICIENCY
Constraints of implementing high power solutions
are the power dissipation and the size of the
power supply. These are both due to the low effi-
ciency of conventional AB class amplifier ap-
proaches.
Here below (figure 6) is described a circuit pro-
posal for a high efficiency amplifier which can be
adopted for both HI-FI and CAR-RADIO applica-
tions.
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