E981.18A39FB ELMOS Semiconductor, E981.18A39FB Datasheet - Page 10

• Manufacturer Part Number: E981.18A39FB
• Description: Motor / Motion / Ignition Controllers & Drivers 8ch squib driver
• Manufacturer: ELMOS Semiconductor
• Type: Airbag Squib Driverr

Specifications of E981.18A39FB

• Rohs: yes
• Product: Electromechanical Drivers
• Operating Supply Voltage: 5 V
• Supply Current: 4.3 mA
• Operating Temperature: - 40 C to + 95 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-44
• Number Of Outputs: 8
• Power Dissipation: 3.2 W

8-Channel Airbag Squib Driver
E981.18
PRELIMINARY INFORMATION - AUG 01, 2011
4.3
Squib loop and fault modes
Fig. 6 shows exemplarily the squib firing loop, the outputs stage of the IC, the PCB components
generating the energy reserve voltage, the harness and finally the squib igniter.
After the deployment the connection of the squib feed and squib return lines can be a short to ground,
an open pin configuration or any phase in between them. This means the driver output stage has to
withstand a short to GND or a open pin state at any point of the squib loop. Additionally at any point of
the loop a short to battery or to GND can occur in and outside of a firing event, due to a fault mode of
the harness. For a fault mode outside of a firing event, the maximum pulse energy applied to the squib
has to be limited, to avoid an inadvertent deployment. This is also valid if the IC is not supplied. The
EMC capacitors by itself will contribute an energy of :
E
= 0.5 C
U
2
during a fault mode, therefor the max. value for this capacitors has to be limited.
CEMC
EMC
For a fault mode during a firing event no damage of the IC will occur.
Fig. 6: Squib loop
The maximum values for leakage and pulse energy outside of a firing event are given in Table 5 below.
Currents flowing into the circuit pins have positive values.
This document contains information on a pre-production product. ELMOS Semiconductor AG reserves the right to change specifications and information herein without notice.
ELMOS Semiconductor AG
Data Sheet
QM-No.: 25DS0072E.00
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