Integrated i.c. engine ignition coil with driver and ionization detection circuits and multiplexed ionization and coil charge current feedback signals

摘要

This invention is related to the field of internal combustion (IC) engine ignition diagnosis systems. More particularly, it is related to the field of detecting an ionization signal in the combustion chamber of an IC engine using the ionization signal to monitor ignition parameters and diagnose engine performance. In a first preferred embodiment, the present feature of the invention multiplexes both the ionization and driver current feedback signals into one signal, thus reducing cost and making coil packaging easier. The multiplexed signal first outputs the ionization detection signal and then replaces the ionization signal with the charge current feedback signal when the charge command Vin is enabled. In other words, the multiplexed feedback signal outputs the ionization feedback signal and switches to the charge current feedback signal when the charge command Vin is active. In a second preferred embodiment, the present feature of the invention comprises a method and apparatus to multiplex the ignition driver gate signal with both the ignition coil charge current feedback signal and the ionization signal, thus reducing the package pin count by two.