Functional Description; Board Functionality; Table 5. Squib Connectors - STMicroelectronics MB467 User Manual

UM0178
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.
Name
SQH0
SQH1
SQH2
SQH3
SQH4
SQH5
SQH6
SQH7
SQH9
SQH10
SQH11
SQH12
SQL0
SQL1
SQL2
SQL3
SQL4
SQL5
SQL6
Squib connectors
Figure
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Figure 8
Description
High Side Driver Output for Channel 0 for L9658
High Side Driver Output for Channel 1 for L9658
High Side Driver Output for Channel 2 for L9658
High Side Driver Output for Channel 3 for L9658
High Side Driver Output for Channel 4 for L9658
High Side Driver Output for Channel 5 for L9658
High Side Driver Output for Channel 6 for L9658
High Side Driver Output for Channel 7 for L9658
High Side Driver Output for Channel 0 for L9654
High Side Driver Output for Channel 1 for L9654
High Side Driver Output for Channel 2 for L9654
High Side Driver Output for Channel 3 for L9654
Low Side Driver Output for Channel 0 for L9658
Low Side Driver Output for Channel 1 for L9658
Low Side Driver Output for Channel 2 for L9658
Low Side Driver Output for Channel 3 for L9658
Low Side Driver Output for Channel 4 for L9658
Low Side Driver Output for Channel 5 for L9658
Low Side Driver Output for Channel 6 for L9658
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