CIRCUIT AND METHOD FOR CONTROLLING A COIL CURRENT DURING A SOFT SHUT DOWN

A current control circuit for an ignition system (i.e., igniter current limiter) is disclosed. The current control circuit can reduce a coil current over a soft shut down (SSD) period using an insulated gate bipolar transistor (IGBT) that is controlled by a negative feedback loop, which controls the current limit of the IGBT according to a SSD profile. In order to prevent an unwanted current rise during the soft shut down period, the current control circuit compares a gate voltage of the IGBT to a reference signal and based on the comparison can enable the SSD profile to include a fast ramp. The fast ramp quickly lowers the current limit of the IGBT so that the coil current equals the current limit and can be controlled by the negative feedback loop.