System and method for impulse noise suppression for integrator-based ion current signal processor

An impulse noise suppression circuit (40) for an integrator-based ion current signal processing system includes a one-shot circuit (56) activated by a trigger signal (54) that is produced when a noise transient (44) in a bandpass filtered ion current signal exceeds a predetermined threshold. The output pulse (86) of the one-shot circuit is selected to have a pulse width (T) configured to mask a substantial portion of the noise transient (44) without masking the remaining filtered ion current signal during the remainder of a knock window (KWI) in which knock is detected.