5.3
Inductive Load
BTS5180-2EKA
Power Stage
5.3.1 Output Clamping
When switching OFF inductive loads with high side switches, the voltage VOUT drops below ground potential,
because the inductance intends to continue driving the current. To prevent the destruction of the device by
avalanche due to high voltages, there is a voltage clamp mechanism ZDS(AZ) implemented that limits negative
output voltage to a certain level (VS - VDS(AZ)). Please refer to Figure 10 and Figure 11 for details. Nevertheless,
the maximum allowed load inductance is limited.
VBAT
VS
ZDS(AZ)
IN
LOGIC
VIN
GND
ZGND
OUT
IL
L, RL
VDS
VOUT
Figure 10 Output Clamp (OUT0 and OUT1)
IN
Output clamp.svg
VOUT
VS
VS-VDS(AZ)
IL
Figure 11 Switching an Inductive Load Timing
t
t
t
Switching an inductance.vsd
Data Sheet
PROFET™+ 12V
16
Rev. 2.1, 2011-09-01