Smart High-Side Power Switch
BTS721L1
Inductive load switch-off energy
dissipation
ꢃꢃ
ꢋ
ꢋ
:ꢇ
ꢋ
ꢏꢐꢖꢝ
ꢂ
ꢃꢃ
ꢄꢅ
ꢍꢎꢈ
ꢀꢁꢂꢃꢄꢅ
ꢏ
ꢓ
ꢇꢈ
ꢋ
ꢏ
%ꢅꢌ
4
ꢏ
ꢀ
ꢋ
#
#
ꢏ
Energy stored in load inductance:
2
L
1
E =
L
/
·L·I
2
While demagnetizing load inductance, the energy
dissipated in PROFET is
E = Ebb + EL - ER=
AS
V
·i (t) dt,
ON(CL) L
with an approximate solution for R > 0Ω:
L
I ·L
L
I ·R
L L
OUT(CL)
E =
AS
(V
+|V |) ꢀꢁꢂ(1+
OUT(CL)
)
bb
2·R
|V
|
L
Maximum allowable load inductance for
5)
a single switch off (one channel)
ꢀꢁꢂꢁꢃꢁꢄꢅ ꢆꢇꢁT
= 150°C, V = 12 V, R = 0 Ω
ꢀꢁ
j,start
bb
L
L [mH]
ꢆ....
ꢆ...
ꢆ..
ꢆ.
ꢆ
ꢆ
ꢊ
'
(
)
/
*
+
I
[A]
L
Data Sheet
11
Rev. 1.3, 2010-03-16
INFINEON [ Infineon ]
