18
9120A–AUTO–01/08
ATA6831/ATA6832 Driver ICs
8.2
Inductive Shutdown
A driver IC faces a challenge when an inductive load is connected to its outputs as the energy
stored in the inductance leads to a voltage peak when the load is switched off. An inductive load
connected to the low-side driver outputs causes a voltage peak with positive polarity, while for
the high-side outputs such peak is negative. In order to prevent any damage to the IC's output
stages, some protective measures have to be implemented.
illustrates the principle
protection circuit of the outputs.
Figure 8-3.
Principle Clamping Structure at a Driver Stage
The clamping structures at the output stages limit the voltage peak and provide a path for the
current after switching off. The maximum inductive shutdown energy for ATA6831 is specified as
15 mJ. This value applies for both low-side and high-side outputs. The energy, WL, stored in the
inductor L during the switched-on state can be calculated using the following formula:
OUTy
ATA6831
VS
OUTx
W
L
L
I
L
2
×
2
---------------
=
