Datasheet

Data Sheet 17 Rev. 1.1, 2011-09-01
Smart Low-Side Power Switch
BTS3205G
Protection FunctionsShort Circuit Protection
6.3 Short Circuit Protection
The condition short circuit is an overload condition of the device. If the current reaches the value of I
lim
the device
starts to limit the current. In the condition of current limitation the device heats up. If the thermal shutdown
temperature is reached the device turns off. Figure 15 shows this behavior. During the current limitation the input
current is above
I
INnom
. During the time period t
dlim
, the current can be above I
lim
.
Figure 15 Short Circuit Behavior of BTS3205G
As the device is a low side switch it can be assumed that the Source to Ground path has a neglectable low
impedance and resistance. Therefore all impedance and resistance in the load path during short circuit is merged
into Zsc.
IN
0
5V
t
T
J
T
JSD
I
IN
I
INnom
0
I
INlim
Short_cir cuit.em f
Tur n off due to over tem perature
I
D
I
lim
Restart after shor t circuit turn off
Restart into norm al load condition
V
bb
/Z
sc
ΔT
JSD
t
t
t
Occurr ence of Over cur rent
or high ohmic Short cir cuit
t
d lim