8-Channel Squib Driver with Current Counter | E981.21

The Eight Channel Squib Driver ASSP E981.21 is designed spe-cifically for automotive airbag applications. The IC provides individual control and diagnostics for 8 floating squibs. It has two sources of control, an arming sensor signal and a μC sig-nal via the SPI bus. An active signal at the arming sensor in-put 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 order to limit the power dissipation of the driver stages, internal firing limita-tion counters (FTL) are implemented for each high side driver. Additionally an over voltage detection for all 8 LSD (VTxL) out-put 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.