Datasheet

Data Sheet BTS555
Infineon Technologies AG 9 2010-June-01
Reverse battery protection
Logic
IS
IN
IS
R
V
R
OUT
L
R
Power GND
Signal GND
V
bb
-
Power
Transistor
IN
R
bb
R
D
S
D
R
V
≥ 1 kΩ, R
IS
= 1 kΩ nominal. Add R
IN
for reverse
battery protection in applications with V
bb
above
16
V
18)
; recommended value:
1
R
IN
+
1
R
IS
+
1
R
V
=
0.1A
|V
bb
| - 12V
if D
S
is not used (or
1
R
IN
=
0.1A
|V
bb
| - 12V
if D
S
is
used).
To minimize power dissipation at reverse battery
operation, the summarized current into the IN and IS
pin should be about 120mA. The current can be
provided by using a small signal diode D in parallel to
the input switch, by using a MOSFET input switch or by
proper adjusting the current through R
IS
and R
V
.
V
bb
disconnect with energized inductive
load
Provide a current path with load current capability by
using a diode, a Z-diode, or a varistor. (V
ZL
< 72 V or
V
Zb
< 30 V if R
IN
=0). For higher clamp voltages
currents at IN and IS have to be limited to 250 mA.
Version a:
PROFET
V
IN
OUT
IS
bb
V
bb
V
ZL
Version b:
PROFET
V
IN
OUT
IS
bb
V
bb
V
Zb
Note that there is no reverse battery protection when
using a diode without additional Z-diode V
ZL
, V
Zb
.
Version c: Sometimes a neccessary voltage clamp is
given by non inductive loads R
L
connected to the same
switch and eliminates the need of clamping circuit:
PROFET
V
IN
OUT
IS
bb
V
bb
R
L