Smart Highside High Current Power Switch

Data Sheet BTS550P
Inverse load current operation
Maximum allowable load inductance for
E AS = IL· L
IL·RL
(V
2·R bb + |V OUT(CL) |) ln (1+
L |V OUT(CL) | ) a single switch off
L = f (I L ); T j,start = 150°C, V bb = 12 V, R L = 0 Ω
V bb
V
bb
- I L
L [µH]
+
IN PROFET OUT
100000
-
IS
V OUT +
V
I IS
IN
10000
-
V IS R IS
1000
The device is specified for inverse load current
operation (V OUT > V bb > 0V). The current sense
feature is not available during this kind of operation
100
(I IS = 0). With I IN = 0 (e.g. input open) only the intrinsic
drain source diode is conducting resulting in
considerably increased power dissipation. If the
10
device is switched on (V IN = 0), this power
dissipation is decreased to the much lower value
R ON(INV) * I 2 (specifications see page 4).
1
Note: Temperature protection during inverse load
current operation is not possible!
1 10 100 1000
I L [A]
Inductive load switch-off energy
Externally adjustable current limit
dissipation
If the device is conducting, the sense current can be
E bb
used to reduce the short circuit current and allow
E AS
higher lead inductance (see diagram above). The
device will be turned off, if the threshold voltage of
E Load T2 is reached by I
V
S
*R IS
. After a delay time defined
bb
by R
i L(t)
V
*C V
T1 will be reset. The device is turned on
V bb
again, the short circuit current is defined by I
IN PROFET OUT
L(SC)
and
the device is shut down after t d(SC)
with latch
E
L function.
IS
L
Z L
{
I IN
R E
V
R L R
bb
IS
V bb
Energy stored in load inductance:
IN PROFET OUT
E L = 1 /2·L·I 2 L
IS
R
While demagnetizing load inductance, the energy
V
R
dissipated in PROFET is
load
IN
E AS = E bb + E L - E R = V ON(CL)·i L (t) dt,
Signal
T1 C V T2
R
IS
Signal
GND
Power
with an approximate solution for R L > 0 Ω:
GND
Infineon Technologies AG Page 10 2000-Mar-24