With Welcome to Freescale Semiconductor 's KT33812ECUUG Integrated circuit

http://www.freescale.com/files/analo...UG.pdf?fsrch=1

KIT33812ECUEVME Product Summary Page

Hi,
Prufrex has actually been building this into Stihl ignitions for some time. Now with the MS-280 they have the Intelligent Engine Management system that adds an extra pair of magnets to the flywheel to give more consistent power for the circuitry to control the carb.
Peace,
Clarke