TDA1905 Datasheet, PDF (12/14 Pages) STMicroelectronics – 5W AUDIO AMPLIFIER WITH MUTING

TDA1905
THERMAL SHUT-DOWN
The presence of a thermal limiting circuit offers the following advantages:
1) An overload on the output (even if it is permanent), 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 damage due to high junction temperature.
If for any reason, the junction temperatureincreases up to 150 °C, the thermal shut-down simply reduces
the power dissipation and the current consumption.
The maximum allowable power dissipation depends upon the size of the external heatsink (i.e. its thermal
resistance); fig. 32 shows this dissipable power as a function of ambient temperature for different thermal
resistance.
Figure 30. Output power
and drain current vs. case
temperature
Figure 31. Output power
and drain current vs. case
temperature
Figure 32. Maximum allo-
wable power dissipation
vs. ambient temperature
MOUNTING INSTRUCTION : See TDA1904
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