Abstract: An igniter includes a switch element and a switch control apparatus. An ignition signal IGT is input to an input line of the switch control apparatus. A high-frequency filter removes high-frequency noise from the input line. A voltage comparator compares an output voltage VFIL of the high-frequency filter with a reference voltage VREF, so as to generate a judgment signal SDET. A driving stage controls an on/off switching operation of the switch element according to the judgment signal SDET. An off-state dead-time circuit prohibits the switch element from turning off during a predetermined dead time after the judgment signal SDET transits to a negated level that corresponds to the off state of the switch element.

Abstract: An igniter that includes switch element and switch control device for controlling the switch element depending on ignition signal. The switch control device includes a determination stage that compares voltage associated with the ignition signal with a predetermined voltage to generate a determination signal, a driving stage that controls ON/OFF operations of the switch element depending on the determination signal, a timer circuit that asserts a conduction protection signal when state where the determination signal becomes an assert level corresponding to an ON operation of the switch element continues for predetermined time, a time-varying voltage generating circuit that generates time-varying voltage over time in response to the assertion of the conduction protection signal, and an amplifier that changes the voltage of a control terminal of the switch element such that detection voltage associated with coil current flowing in the switch element is close to the time-varying voltage.

Abstract: An igniter includes a switch element and a switch control apparatus. An ignition signal IGT is input to an input line of the switch control apparatus. A high-frequency filter removes high-frequency noise from the input line. A voltage comparator compares an output voltage VFIL of the high-frequency filter with a reference voltage VREF, so as to generate a judgment signal SDET. A driving stage controls an on/off switching operation of the switch element according to the judgment signal SDET. An off-state dead-time circuit prohibits the switch element from turning off during a predetermined dead time after the judgment signal SDET transits to a negated level that corresponds to the off state of the switch element.

Abstract: An igniter includes: a switch connected to an ignition coil; and a controller to control the switch according to an ignition signal. The controller includes an ignition signal input; a determination stage comparing a voltage of the input with a reference voltage to generate a determination signal; a drive stage controlling the switch's ON/OFF according to the determination signal; a comparison circuit receiving a first supply voltage, comparing a current on the switch with a reference current, and generating a feedback-signal having a level based on the comparison; an output transistor having one end grounded and the other end connected to an output terminal of an ignition check signal and having a threshold voltage higher than the first supply voltage; and a level-shifter receiving a second supply voltage higher than the threshold voltage, level-shifting the feedback-signal, and outputting the level-shifted feedback-signal to a control terminal of the output transistor.

Abstract: An igniter includes a switch element and a switch control apparatus. An ignition signal IGT is input to an input line of the switch control apparatus. A high-frequency filter removes high-frequency noise from the input line. A voltage comparator compares an output voltage VFIL of the high-frequency filter with a reference voltage VREF, so as to generate a judgment signal SDET. A driving stage controls an on/off switching operation of the switch element according to the judgment signal SDET. An off-state dead-time circuit prohibits the switch element from turning off during a predetermined dead time after the judgment signal SDET transits to a negated level that corresponds to the off state of the switch element.

Abstract: There are provided a signal detection circuit and an igniter capable of enhancing a capability of withstanding breakdown by noise. The signal detection circuit includes an input terminal Sin configured to receive a control signal from an ECU and a bidirectional floating diode provided between the input terminal and a ground. Further, the signal detection circuit includes an attenuation circuit configured to attenuate an output of the bidirectional floating diode, a low-pass filter configured to pass a low-frequency component of the output of the attenuation circuit, and a comparator configured to compare an output of the low-pass filter with a reference voltage.

Abstract: An igniter that includes switch element and switch control device for controlling the switch element depending on ignition signal. The switch control device includes a determination stage that compares voltage associated with the ignition signal with a predetermined voltage to generate a determination signal, a driving stage that controls ON/OFF operations of the switch element depending on the determination signal, a timer circuit that asserts a conduction protection signal when state where the determination signal becomes an assert level corresponding to an ON operation of the switch element continues for predetermined time, a time-varying voltage generating circuit that generates time-varying voltage over time in response to the assertion of the conduction protection signal, and an amplifier that changes the voltage of a control terminal of the switch element such that detection voltage associated with coil current flowing in the switch element is close to the time-varying voltage.

Abstract: An igniter includes: a switch connected to an ignition coil; and a controller to control the switch according to an ignition signal. The controller includes an ignition signal input; a determination stage comparing a voltage of the input with a reference voltage to generate a determination signal; a drive stage controlling the switch's ON/OFF according to the determination signal; a comparison circuit receiving a first supply voltage, comparing a current on the switch with a reference current, and generating a feedback-signal having a level based on the comparison; an output transistor having one end grounded and the other end connected to an output terminal of an ignition check signal and having a threshold voltage higher than the first supply voltage; and a level-shifter receiving a second supply voltage higher than the threshold voltage, level-shifting the feedback-signal, and outputting the level-shifted feedback-signal to a control terminal of the output transistor.

Abstract: An igniter includes a switch element and a switch control apparatus. An ignition signal IGT is input to an input line of the switch control apparatus. A high-frequency filter removes high-frequency noise from the input line. A voltage comparator compares an output voltage VFIL of the high-frequency filter with a reference voltage VREF, so as to generate a judgment signal SDET. A driving stage controls an on/off switching operation of the switch element according to the judgment signal SDET. An off-state dead-time circuit prohibits the switch element from turning off during a predetermined dead time after the judgment signal SDET transits to a negated level that corresponds to the off state of the switch element.

Abstract: There are provided a signal detection circuit and an igniter capable of enhancing a capability of withstanding breakdown by noise. The signal detection circuit includes an input terminal Sin configured to receive a control signal from an ECU and a bidirectional floating diode provided between the input terminal and a ground. Further, the signal detection circuit includes an attenuation circuit configured to attenuate an output of the bidirectional floating diode, a low-pass filter configured to pass a low-frequency component of the output of the attenuation circuit, and a comparator configured to compare an output of the low-pass filter with a reference voltage.