Datasheet

Data Sheet 33 Rev. 2.1, 2011-09-01
PROFET™+ 12V
BTS5045-2EKA
Diagnostic Functions
7.3.4 SENSE Signal with OUT in Short Circuit to V
S
In case of a short circuit between the OUTput-pin and the V
S
pin, all or portion (depending on the short circuit
impedance) of the load current will flow through the short circuit. As a result, a lower current compared to the
normal operation will flow through the DMOS of the BTS5045-2EKA, which can be recognized at the SENSE
signal. The open load at OFF detection circuitry can also be used to distinguish a short circuit to
V
S
. In that case,
an external resistor to ground
R
SC_VS
is required. Figure 27 gives a sketch of the situation.
Figure 27 Short Circuit to Battery Detection in OFF Electrical Equivalent Circuit
7.3.5 SENSE Signal in Case of Overload
An overload condition is defined by a current flowing out of the DMOS reaching the current limitation and / or the
absolute dynamic temperature swing
T
J(SW)
is reached, and / or the junction temperature reaches the thermal
shutdown temperature
T
J(SC)
. Please refer to Chapter 6.5 for details.
In that case, the SENSE signal given is by
I
IS(FAULT)
when the diagnostic is selected.
The device has a thermal restart behavior, such that when the overtemperature or the exceed dynamic
temperature condition has disappeared, the DMOS is reactivated if the IN is still at logical level one. If the DEN
pin is activated, and DSEL pin is selected to the correct channel, SENSE is not toggling with the restart mechanism
and remains to
I
IS(FAULT)
.
7.3.6 SENSE Signal in Case of Inverse Current
In the case of inverse current, the sense signal of the affected channel will indicate open load in OFF state and
indicate open load in ON state. The unaffected channel indicates normal behavior as long as the
I
INV
current is not
exceeding the maximum value specified in Chapter 5.4.
V
S
V
bat
V
OL(OFF)
I
IS(FAULT)
IS
OL
comp.
Short circuit to Vs.svg
V
BAT
OUT
GND
Z
GND
R
SC_VS
R
IS