Datasheet

BTS5045-2EKA
Protection Functions
Data Sheet 22 Rev. 2.1, 2011-09-01
PROFET™+ 12V
Figure 15 Undervoltage Behavior
6.3 Overvoltage Protection
There is an integrated clamp mechanism for overvoltage protection (Z
D(AZ)
). To guarantee this mechanism
operates properly in the application, the current in the Zener diode has to be limited by a ground resistor. Figure 16
shows a typical application to withstand overvoltage issues. In case of supply voltage higher than
V
S(AZ)
, the power
transistor switches ON and the voltage across the logic section is clamped. As a result, the internal ground
potential rises to
V
S
- V
S(AZ)
. Due to the ESD Zener diodes, the potential at pin INx, DSEL and DEN rises almost
to that potential, depending on the impedance of the connected circuitry. In the case the device was ON, prior to
overvoltage, the BTS5045-2EKA remains ON. In the case the BTS5045-2EKA was OFF, prior to overvoltage, the
power transistor can be activated. In the case the supply voltage is in above
V
BAT(SC)
and below V
DS(AZ)
, the output
transistor is still operational and follows the input. If at least one channel is in the ON state, parameters are no
longer guaranteed and lifetime is reduced compared to the nominal supply voltage range. This especially impacts
the short circuit robustness, as well as the maximum energy
E
AS
capability. Z
GND
as a resistor (150 Ω) will offer
superior results compared to a diode and resistor (1 kΩ).
Figure 16 Overvoltage Protection with External Components
undervoltage behavior.vsd
V
OUT
V
S(OP)
V
S(UV)
V
S
INx
DEN
IS
ZD
ESD
GND
OUTx
V
S
V
BAT
Z
D(AZ)
LOGIC
DSEL
Overvoltage protection.svg
Z
DS(AZ)
IN0
IN1
R
IN
R
DEN
R
DSEL
R
SENSE
R
IS
I
SOV
Z
IS(AZ)
Z
GND