TDA7245 Datasheet, PDF (9/11 Pages) STMicroelectronics – 5W AUDIO AMPLIFIER WITH MUTING AND STAND-BY

TDA7245
THERMAL SHUTDOWN
The presence of a thermal limiting circuit offers
the following advantages:
1)An overload on the output (even if it is perma-
nent), or an above limit ambient temperature
can be easily tolerated since the Tj cannot be
higher than 150°C.
2)The heatsink can have a smaller factor of
safety compared with that of a conventional
circuit. There is no possibility of device dam-
age due to high junction temperature.
If for any reason, the junction temperature in-
crease up to 150°C, the thermal shutdown
simply reduces the power dissipation and the
current consumption.
The maximum allowable power dissipation de-
pends upon the junction-ambient thermal resis-
tance. Fig. 21 shows this dissipable power as a
function of ambient temperature for different ther-
mal resistance.
Figure 21: Maximum Allowable Power
Dissipation vs. Ambient Temperature
MOUNTING INSTRUCTIONS
The TDA7245 is assembled in the POWERDIP, in
which 9 pins (from 10 to 18) are attached to the
frame and remove the heat produced by the chip.
Figure 22 shows a PC Board copper area used
as a Heatsink (l = 65mm). The Thermal Resis-
tance Junction-Ambient is 35°C.
Figure 22: Example of Heatsink using PC Board
Copper (l = 65mm)
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