TDA7375A Datasheet, PDF (10/14 Pages) STMicroelectronics – 2 x 37W DUAL/QUAD POWER AMPLIFIER FOR CAR RADIO

TDA7375A
rect operation for the device itself and for the
loudspeaker.
This particular kind of protection acts in such a
way to avoid the device is turned on (by ST-BY)
when a resistive path (less than 16 ohms) is pre-
sent between the output and GND. As the in-
volved circuitry is normally disabled when a cur-
rent higher than 5mA is flowing into the ST-BY
pin, it is important, in order not to disable it, to
have the external current source driving the ST-
BY pin limited to 5mA.
This extrafunction becomes particularly attractive
when, in the single ended configuration, one ca-
pacitor is shared between two outputs (see fig.
21).
Figure 22: Clipping Detection Waveforms
Figure 21.
A current sinking at pin 10 is provided when a cer-
tain distortion level is reached at each output. This
function allows gain compression facility when-
ever the amplifier is overdriven.
Supposing that the output capacitor Cout for any
reason is shorted, the loudspeaker will not be
damaged being this soft short circuit condition re-
vealed.
Thermal Shutdown
In this case the output 10 will signal the proximity
of the junction temperature to the shutdown
threshold. Typically current sinking at pin 10 will
start ~10°C before the shutdown threshold is
reached.
HANDLING OF THE DIAGNOSTIC INFORMA-
Figure 23: Output Fault Waveforms (see fig. 24)
Diagnostic Facilities
The TDA7375 is equipped with a diagnostic cir-
cuitry able to detect the following events:
Clipping in the output signal
Thermal shutdown
Output fault:
– short to GND
– short to VS
– soft short at turn on
The information is available across an open
collector output (pin 10) through a current sink-
ing when the event is detected
TDA7375A
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