UM0178
4 Hardware
19/37
4.7.2 Functional
description
The Airbag Eva Board supports up to 12 squibs.
Upon receiving a valid deployment condition, the respective SQH and SQL drivers are turned
on. SQH and SQL drivers are also turned on momentarily during a MOS diagnostic. Otherwise,
SQH and SQL are inactive under any normal, fault, or transient conditions. Upon a successful
deployment of the respective SQH and SQL drivers, a deploy command success flag is
asserted via SPI. Only a valid deployment condition can turn on the respective SQH and SQL
drivers.
4.7.3 Board
functionality
Squib can be connected directly to the ASIC’s through TP1, TP2 and TP7.
A loss of ground can be simulated by opening one of the jumpers insert in J13, J16, J17, J18,
J19.When any of the grounds (GND0 – 7, GND9 - 12) are lost, no deployment can occur to the
respective deployment channels. A loss of ground condition on one or several channels will not
affect the operation of the remaining channels.
When a loss of ground condition occurs, the source of the low side MOS will be floating. In this
case, no current will flow through the low side driver. This condition will be detected as a fault
by a low side MOS diagnostic.
Table 5.
Squib connectors
Name
Figure
Description
SQH0
Figure 8
High Side Driver Output for Channel 0 for L9658
SQH1
Figure 8
High Side Driver Output for Channel 1 for L9658
SQH2
Figure 8
High Side Driver Output for Channel 2 for L9658
SQH3
Figure 8
High Side Driver Output for Channel 3 for L9658
SQH4
Figure 8
High Side Driver Output for Channel 4 for L9658
SQH5
Figure 8
High Side Driver Output for Channel 5 for L9658
SQH6
Figure 8
High Side Driver Output for Channel 6 for L9658
SQH7
Figure 8
High Side Driver Output for Channel 7 for L9658
SQH9
Figure 8
High Side Driver Output for Channel 0 for L9654
SQH10
Figure 8
High Side Driver Output for Channel 1 for L9654
SQH11
Figure 8
High Side Driver Output for Channel 2 for L9654
SQH12
Figure 8
High Side Driver Output for Channel 3 for L9654
SQL0
Figure 8
Low Side Driver Output for Channel 0 for L9658
SQL1
Figure 8
Low Side Driver Output for Channel 1 for L9658
SQL2
Figure 8
Low Side Driver Output for Channel 2 for L9658
SQL3
Figure 8
Low Side Driver Output for Channel 3 for L9658
SQL4
Figure 8
Low Side Driver Output for Channel 4 for L9658
SQL5
Figure 8
Low Side Driver Output for Channel 5 for L9658
SQL6
Figure 8
Low Side Driver Output for Channel 6 for L9658
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
