Patent ID: 7293554

Claim:
A circuit for driving an ignition coil, the circuit comprising: a switching portion in electrical communication with the ignition coil for providing a current path; and a rate limiting portion in electrical communication with the switching circuit, the rate limiting portion being configured to control a voltage transition time as the switching portion transitions from a non-conducting mode to a fully conducting mode, wherein the switching portion includes: a first transistor connected in electrical series with the ignition coil; a second transistor connected to the control input of the first transistor; a capacitor connected in electrical series between the switched side of the ignition coil and the control input of the second transistor; and a diode connected in series between the control input of the second transistor and the capacitor to isolate the control input of the second transistor from the capacitor as the first transistor transitions from a fully conducting to a non-conducting mode.