Datasheet

Datasheet 15 Rev. 1.0, 2008-08-28
Smart High-Side Power Switch
BTS50080-1TEA
Protection Functions
6 Protection Functions
The device provides embedded protective functions. Integrated protection functions are designed to prevent IC
destruction under fault conditions described in the data sheet. Fault conditions are considered as “outside” normal
operating range. Protection functions are neither designed for continuous nor repetitive operation.
6.1 Overload Protection
The load current I
L
is limited by the device itself in case of overload or short circuit to ground. There are multiple
steps of current limitation
I
Lx(SC)
which are selected automatically depending on the voltage drop V
ON
across the
power DMOS. Please note that the voltage at the OUT pin is
V
bb
- V
ON
. Figure 11 shows the dependency for a
typical device.
Figure 11 Typical Current Limitation
Depending on the severity of the short condition as well as on the battery voltage the resulting voltage drop across
the device varies.
Whenever the resulting voltage drop
V
ON
exceeds the short circuit detection threshold V
ON(SC)
, the device will
switch off immediately and latch until being reset via the input. The V
ON(SC)
detection functionality is activated,
when
V
bIN
> 10 V typ. and the blanking time t
d(SC1)
expired after switch on.
In the event that either the short circuit detection via
V
ON(SC)
is not activated or that the on chip temperature sensor
senses overtemperature before the blanking time
t
d(SC1)
expired, the device switches off resulting from
overtemperature detection. After cooling down with thermal hysteresis, the device switches on again. The device
will react as during normal switch on triggered by the input signal. Please refer to Figure 12 and Figure 19 for
details.
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