BTS 824R
Infineon Technologies AG 10 2003-Oct-01
GND disconnect with GND pull up
PROFET
V
IN
ST
OUT
GND
bb
V
bb
V
GND
V
IN
V
ST
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
V
bb
high
For inductive load currents up to the limits defined by Z
L
(max. ratings and diagram on page 10) each switch is
protected against loss of V
bb
.
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
PROFET
V
IN
ST
OUT
GND
bb
=
E
E
E
E
AS
bb
L
R
E
Load
R
L
L
{
L
Z
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
Ω:
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 (one channel)
4)
L = f (I
L
); T
j,start
=
150°C, V
bb
= 12 V, R
L
= 0 Ω
Z
L
[mH]
1
10
100
1000
1234567891011
I
L
[A]
