L6375 Ver la hoja de datos (PDF) - STMicroelectronics
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L6375 Datasheet PDF : 12 Pages
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L6375
ditions may occur
A) the overload is still present, and then the output power MOS is again driven in linear mode (limiting
the output current to Isc) for another Ton, starting a new cycle, or
B) the overload condition is removed, and the output power MOS is no longer driven in linear mode.
All these occurrences are presented on the DIAG2 pin (see fig 2).
We call this unique feature Non Dissipative Short Circuit Protection and it ensures a very safe operation even
in permanent overload conditions. Note that choosing the most appropriate value for the Ton interval (i.e. the
value of the Cdon capacitor) a delay (the Ton itself) will prevent that a misleading Short Circuit information is
presented on the DIAG2 output, when driving capacitive loads (that acts like short circuit in the very beginning)
or Incandescent Lamp (a cold filament has a very low resistive value). The Non Dissipative Short Circuit Pro-
tection can be disabled (keeping Ton = 0 but with the output current still limited to Isc, and Diagnostic dis-
abled)simply shorting to ground the the ON DELAY pin.
Figure 2. Non Dissipative Short Circuit Protection Operation
OUTPUT
CURRENT
Isc
Iout
DIAG
(active low)
t<tON
Short Circuit
tON
tOFF
tON
tOFF
Short Circuit
Time
D94IN105
Time
DIAGNOSTIC LOGIC
The operating conditions of the device are permanently monitored and the following occurrences are signalled
via the DIAG1/DIAG2 open-drain output pins see: diagnostic Truth Table.
- Short Circuit versus ground.
- Short Circuit versus VS.
- Under Voltage(UV)
- Over Temperature (OVT)
- Open Load, if the output current is less than 3mA (typical value).
DEMAGNETIZATION OF INDUCTIVE LOADS
An internal zener diode, limiting the voltage across the Power MOS to between 50 and 60V (Vcl), provides safe
and fast demagnetization of inductive loads without external clamping devices. The maximum energy that can
be absorbed from an inductive load is specified as 200mJ (at Tj = 85°C)
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