Datasheet

Datasheet 11 Rev. 1.0, 2008-08-28
Smart High-Side Power Switch
BTS50080-1TEB
Power Stages
Figure 8 Switching an Inductance
5.3.1 Maximum Load Inductance
While de-energizing inductive loads, energy has to be dissipated in the BTS50080-1TEB. This energy can be
calculated via the following equation:
In the event of de-energizing very low ohmic inductances (
R
L
≈0) the following, simplified equation can be used:
The energy, which is converted into heat, is limited by the thermal design of the component. For given starting
currents the maximum allowed inductance is therefore limited. See Figure 9 for the maximum allowed inductance
at V
bb
=12V.
V
OUT
InductiveLoad. emf
t
I
L
t
V
OUT(CL)
V
bb
ON OFF
V
ON(CL)
EV
ON CL()
V
bb
V
ON CL()
–
R
L
------------------------------------
ln⋅ 1
R
L
I
L
⋅
V
ON(CL)
V
bb
–
-----------------------------------+


I
L
+
L
R
L
----- -
⋅⋅=
E
1
2
-- -
LI
L
2
V
ON(CL)
V
ON(CL)
V
bb
–
-----------------------------------
⋅=