Abstract: An ignition system for an internal combustion engine includes an ignition coil coupled to a spark plug in a combustion chamber of the engine, and a switch responsive to an ignition control signal for causing a primary current to flow through a primary winding of the ignition coil. A control circuit is configured to generate the ignition control signal so as to produce a plurality of sparks at the spark plug during a combustion event in the cylinder. A combustion detection circuit in sensing relation with the combustion cylinder is configured to generate a combustion detect signal when combustion occurs. The control circuit is further configured to terminate the generation of the ignition control signal during the combustion event in response to the combustion detect signal, thereby terminating multicharge operation when the need for further sparks is no longer present. Unnecessary spark plug wear is avoided.

Abstract: A transient protection circuit (14) includes a resistor (22) having a first end adapted for connection to a first signal line (16) of a voltage supply (12) and a second opposite end connected to a voltage supply input (20) of an application circuit (18). In one embodiment, the resistor (22) defines an emitter (26) of a PNP transistor (24) having a floating base (28) and a collector (30) adapted for connection to a reference signal line (15) of the voltage supply (12). In an alternative embodiment (14′), the emitter (26) of the PNP transistor (24) is connected to the first end of the resistor (22). The transient protection circuit (14, 14′) is preferably formed on a monolithic integrated circuit including the application circuit (18) wherein a semiconductor layer (46) defining the first input to the resistor (22) also defines a bond pad (50).

Abstract: Circuitry for driving an electrical load (18) and regulating a load current (IL) therethrough includes a multiple output load driving device (20) having an input (26) receiving a gate drive signal (GD) thereat and operable to direct the load current (IL) therethrough from a collector (28) to main (22) and sense (24) outputs thereof. A control circuit is provided including an error amplifier (52) having a non-inverting input operable to receive a reference voltage and an inverting input operable to receive a sense voltage proportional to the portion of load current (IL) flowing through the sense output (24) of the load driving device (20), and producing an output based thereon to which a gate drive control circuit (54) is responsive to supply the gate drive signal (GD). A feedback capacitor (CFB) is disposed between the collector (28) of the load driving device (20) and a resistor string (R8, R9, RTRIM) establishing the reference voltage, and provides an AC coupling therebetween.

Abstract: An amplifier circuit (14') for canceling variations in an amplifier feedback signal includes compensation circuitry (50) defining a replica of the feedback current therethrough. The replicated feedback current is drawn from a circuit node (N1) which directs the feedback signal to a differential pair (Q1, Q2) of the amplifier circuit 14', whereby any biasing effects on the differential pair (Q1, Q2) due to changes in the feedback signal resulting from changes in a gate drive output voltage (V.sub.GD) of the amplifier circuit (14') are eliminated. Accordingly, the gate drive output voltage (V.sub.GD) may be used to control an ignition coil (L1) drive transistor (16) whereby any changes in gate drive voltage (V.sub.GD) will not cause the coil current (I.sub.L) to deviate from its target coil current limit value.

Abstract: The ignition coil driver module of the present invention includes a control integrated circuit, formed of a low voltage semiconductor material, and a high current load driver integrated circuit, formed of a high voltage integrated circuit, housed within a common package. The high current load driver integrated circuit is responsive to a low voltage drive signal provided by the control integrated circuit to permit a load current to flow unrestricted through the load driver integrated circuit and an inductive load connected thereto. The control integrated circuit includes a sense resistor which receives the load current from the high current load driver integrated circuit, converts this current to a sense voltage, compares the sense voltage to a reference voltage generated within the control integrated circuit, and forces the low voltage drive signal to drop to a level which will limit the load current to a predetermined current value.

Abstract: An electrical input buffer circuit is provided for receiving an input signal such as an electronic spark timing signal and providing an output signal despite the presence of noise. The input buffer circuit receives a control signal and a reference voltage signal, and the voltage potential therebetween provides a differential input. A voltage divider network is coupled between the inputs for producing a first voltage potential and a second voltage potential in response to the differential input. A differential pair of NPN type transistors compares the control signal to a threshold value. The input buffer circuit produces an output high or low signal as a function of the input control voltage and is allowed to operate above and below local ground.

Abstract: An automotive ignition control system includes a vehicle control computer operable to provide electronic spark timing (EST) signals, a control circuit having a number of coil drive circuits connected thereto, a corresponding number of coil driver devices connected to respective ones of the coil drive circuits and a corresponding number of ignition coils connected to respective ones of the coil driver devices. The control circuit is responsive to an active state of any one of the EST signals to activate a corresponding one of the coil driver devices while inhibiting activation of all others. If any EST signal remains in an active state for an excessive time period, the control circuit is operable to lock-out the corresponding coil driver device from operation until such a fault condition is cleared. The control circuit is preferably operable to accomplish the lock-out function by gradually decreasing the coil current associated with the faulty EST signal in a fashion that does not generate a spark event.