tda7375a STMicroelectronics, tda7375a Datasheet - Page 10

• Manufacturer Part Number: tda7375a
• Description: 2 X 37w Dual/quad Power Amplifier For Car Radio
• Manufacturer: STMicroelectronics

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 21.
Supposing that the output capacitor C
reason is shorted, the loudspeaker will not be
damaged being this soft short circuit condition re-
vealed.
Diagnostic Facilities
The TDA7375 is equipped with a diagnostic cir-
cuitry able to detect the following events:
10/14
– short to GND
– short to V
– 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
Clipping in the output signal
Thermal shutdown
Output fault:
S
out
for any
Figure 22: Clipping Detection Waveforms
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.
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)
TDA7375A