E981.20 | 4-Channel Squib Driver with Current Counter


The Four Channel Squib Driver ASSP E981.20 is designed spe-cifically for automotive airbag applications. The squib driv-er provides individual control and diagnostics for 4 floating squibs. It has two sources of control, an arming sensor signal and a μC signal via the SPI bus. An active signal at the arm-ing sensor input will activate all selected drivers, which have been enabled by the μC. During firing the squibs, the input voltage of the high side switch is limited to 25V for LCM and HCM2 Mode and to 35V in HCM1 Mode by the system. In or-der to limit the power dissipation of the driver stages, internal firing limitation counters (FTL) are implemented for each high side driver. Additionally an over voltage detection for all 4 LSD (VTxL) output voltages is provided to avoid a damage of the drivers in case of a short to battery during firing and during driver test in application.


  • Two squib current modes (LCM and HCM) selectable via SPI commands
  • Simultaneously firing of 4 loops possible
  • Squib channel diagnostics, monitoring and current counter
  • Autarky voltage & squib supply voltage diagnostics
  • Separate low side and high side driver control
  • Serial interface (SPI synchronous communication) to μC (3.3V and 5V tolerant inputs)


  • Squib driver in a Restraint Diagnostic and control Module (RDM)

Ordering Information

  • Samples
    Part No.Temp. RangePackageOrder No.
    E981.20-40°C to +95°CQFN44L7E98120A39B


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Application Diagram

4-Channel Squib Driver with Current Counter