Datasheet

Smart Low-Side Power Switch
BTS3405G
Protection FunctionsOvervoltage Protection
Data Sheet 16 Rev. 1.1, 2011-09-01
Figure 14 Switching an Inductance
While demagnetization of inductive loads, energy has to be dissipated in the BTS3405G. This energy can be
calculated with following equation:
(1)
Following equation simplifies under assumption of
R
L
= 0
(2)
IN
0
5V
t
t
V
D
V
bb
InductiveLoad.emf
t
I
D
V
Clamp
Turn off due to
over temperature or short circuit
EV
bb
V
out CL()
+()
V
out CL()
R
L
------------------------
1
R
L
I
L
⋅
V
out CL()
------------------------+
⎝⎠
⎜⎟
⎛⎞
I
L
+ln⋅
L
R
L
------
⋅⋅=
E
1
2
---
LI
L
2
1
V
bb
V
out CL()
V
bb
–
--------------------------------------+
⎝⎠
⎜⎟
⎛⎞
⋅=