TDA7562B Datasheet, PDF (16/30 Pages) STMicroelectronics – 4 x 46 W multifunction quad power amplifier with built-in diagnostics features

Diagnostics functional description
Figure 22. Restart timing without diagnostic enable (permanent)
Each 1 ms time, a sampling of the fault is done
 M3
M3
M3 M3
M3
TDA7562B
/UT
4.3
/VERCUR RENTAND SHOR T
CIRCUIT PROTECT IONI NTERVENT ION
IESHOR TCIRCUI TT O'.$
T
3HOR TCIRCUI TREMOVED
Figure 23. Restart timing with diagnostic enable (permanent)
 M3
M3
M3
M3
'!0'03
/VERCURRENT ANDSHORT
CIRCUITPROTECTI ON IN TERVENTI ON
IES HORTC IRCUI TTO'.$
T
3HO RTCIRCUIT REMOVED
'!0'03
Output DC offset detection
Any DC output offset exceeding ±2V are signalled out. This inconvenient might occur as a
consequence of initially defective or aged and worn-out input capacitors feeding a DC
component to the inputs, so putting the speakers at risk of overheating.
This diagnostic has to be performed with low-level output AC signal (or V_in = 0).
The test is run with selectable time duration by microprocessor (from a "start" to a "stop"
command):
Start = Last reading operation or setting IB1 - D5 - (OFFSET enable) to 1
Stop = Actual reading operation
Excess offset is signalled out if persistent throughout the assigned testing time. This feature
is disabled if any overloads leading to activation of the short-circuit protection occurs in the
process.
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Doc ID 17984 Rev 2