
BTS436L2
Semiconductor Group
Page 8
2003-Oct-01
GND disconnect with GND pull up
PROFET
V
IN
ST
OUT
GND
bb
Vbb
1
2
4
3
5
VGND
VINVST
Any kind of load. If V
GND >
V
IN
-
V
IN(T+)
device stays off
Due to V
GND
>0, no V
ST
= low signal available.
V
bb
disconnect with energized inductive
load
PROFET
V
IN
ST
OUT
GND
bb
Vbb
1
2
4
3
5
high
For inductive load currents up to the limits defined by ZL
(max. ratings and diagram on page 8) each switch is
protected against loss of Vbb.
Consider at your PCB layout that in the case of Vbb dis-
connection with energized inductive load all the load current
flows through the GND connection.
Inductive Load switch-off energy
dissipation
E
bb
PROFET
V
IN
ST
OUT
GND
bb
=
E
E
EAS
L
R
ELoad
L
R
L
{
Z
L
Energy stored in load inductance:
E
L
=
1/2
·
L
·
I
2
L
While demagnetizing load inductance, the energy
dissipated in PROFET is
E
AS
= E
bb
+ E
L
- E
R
=
V
ON(CL)
·
i
L
(t) dt,
with an approximate solution for R
L
>
0
:
E
AS
= I
L
·
L
2
·
R
L
·
(
V
bb
+
|V
OUT(CL)
|)
·
ln
(1+
I
L
·
R
L
|V
OUT(CL)
| )
Maximum allowable load inductance for
a single switch off
L = f (I
L
);
T
j,start
=
150°C,
T
C
=
150°C const.,
V
bb
=
12
V,
R
L
=
0
Z
L
[mH]
1000
1
10
100
0
2
4
6
10
12
14
16
18
0.1
I
L [A]