Datasheet

Data Sheet 17 Rev. 2.1, 2011-09-01
PROFET™+ 12V
BTS5045-2EKA
Power Stage
5.3.2 Maximum Load Inductance
During demagnetization of inductive loads, energy has to be dissipated in the BTS5045-2EKA. This energy can
be calculated with following equation:
(1)
Following equation simplifies under the assumption of
R
L
= 0 Ω.
(2)
The energy, which is converted into heat, is limited by the thermal design of the component. See Figure 12 for the
maximum allowed energy dissipation as a function of the load current.
Figure 12 Maximum Energy Dissipation Single Pulse,
T
J(0)
= 150 °C; V
S
= 13.5V
5.4 Inverse Current Capability
In case of inverse current, meaning a voltage V
INV
at the OUTput higher than the supply voltage V
S
, a current I
INV
will flow from output to V
S
pin via the body diode of the power transistor (please refer to Figure 13). The output
stage follows the state of the IN pin, except if the IN pin goes from OFF to ON during inverse. In that particular
case, the output stage is kept OFF until the inverse current disappears. Nevertheless, the current
I
INV
should not
be higher than
I
L(INV)
. Otherwise, the second channel can be corrupted and erratic behavior can be observed. If
the affected channel is OFF, the diagnostic will detect an open load at OFF. If the affected channel is ON, the
diagnostic will detect open load at ON (the overtemperature signal is inhibited). At the appearance of
V
INV
, a
parasitic diagnostic can be observed at the unaffected channel. After, the diagnosis is valid and reflects the output
state. At
V
INV
vanishing, the diagnosis is valid and reflects the output state. During inverse current, no protection
function are available.
EV
DS AZ()
L
R
L
------
×
V
S
V
DS AZ()
–
R
L
--------------------------------
1
R
L
I
L
×
V
S
V
DS AZ()
–
--------------------------------
–
⎝⎠
⎛⎞
ln
I
L
+××=
E
1
2
---
LI
2
1
V
S
V
S
V
DS AZ()
–
--------------------------------
–
⎝⎠
⎛⎞
×××=
1
10
100
1000
0123456
I
L
[A]
E
AS
[mJ]
EAS45.vsd