Abstract: A control system (100, 200) and method (300) are provided where a first voltage domain circuit (111) and a power switch (121) operate in a first voltage domain and where a second voltage domain circuit (109) operates in a second voltage domain, where the second voltage domain circuit includes a gate driver circuit (202) for providing a control terminal driving signal (PWM1) to drive the power switch, and also includes a watchdog communication circuit (207) for scheduling watchdog communications between the first and second voltage domain circuits to be temporally separated from noise-inducing signal transitions in the control terminal driving signal.

Abstract: In one embodiment, a control system includes a first voltage domain circuit. The first voltage domain circuit includes circuitry for operating in a first voltage domain. The control system includes a second voltage domain circuit. The second voltage domain circuit includes circuitry for operating in a second voltage domain. The second voltage domain circuit includes a driver circuit. The driver circuit for providing a control terminal driving signal to make conductive a power switch. The second voltage domain circuit includes a replication circuit, the replication circuit having an output to provide a replicated signal of the control terminal driving signal. The control system includes a galvanic isolation barrier signal path between the first voltage domain circuit and the second voltage domain circuit. The replicated signal is provided by the second voltage domain circuit to the first voltage domain circuit via the galvanic isolation barrier signal path.

Abstract: Operation of an insulated gate bipolar transistor (IGBT) is monitored by an apparatus that has a capacitor connected between a collector of the IGBT and an input node. A processing circuit, coupled to the input node, responds to current flowing through the capacitor by providing an indication whether a voltage level at the collector is changing and the rate of that change. The processing circuit also employs the capacitor current to provide an output voltage that indicates the voltage at the IGBT collector.

Abstract: A segmented driver including at least one drive pin and a sense pin, a driver circuit, a comparator, and a controller. The driver circuit activates a selected drive level between the drive pins and a reference node. The comparator compares a voltage of the sense pin with a threshold voltage and provides a threshold indication when the voltage of the sense pin reaches the threshold voltage. The controller commands the driver circuit to activate a first drive level in response to an off indication, and commands the driver circuit to switch to a second, lower drive level in response to the threshold indication. The driver circuit may be implemented using low resistive current devices. Multiple drive pins may be included, each for selectively activating a corresponding drive path to adjust drive level. The threshold voltage may be set using a current source and resistor, and may be adjusted for temperature.

Abstract: An IC driver includes a resistor detector to detect whether at least a threshold resistance is present between a pin of the IC driver and the gate of an IGBT. The resistor detector can include a comparator that compares a voltage at the collector of the IGBT to a threshold reference voltage (e.g., ground). In response to drive signals of the IC driver being switched off, a parasitic inductance causes a voltage drop at the emitter of the IGBT, and a commensurate voltage drop at the IGBT collector. If the resistance between the IC driver pin and the IGBT gate is lower than a specified level, the voltage drop at the IGBT collector will be such that the collector voltage falls below the threshold reference voltage. In response, the comparator asserts a signal indicating a fault.

Abstract: A circuit is configured for providing reverse battery protection. The circuit includes a load driver circuit having at least a first half-bridge circuit with topside and bottomside transistors coupled at a midpoint node by a first current terminal of both the topside and bottomside transistors. A second current terminal of the bottomside transistor is coupled to a voltage common node. The circuit also includes: a reverse battery protection transistor having a first current terminal coupled to a battery supply node and a second current terminal coupled to a second current terminal of the topside transistor; a bootstrap capacitor having a first terminal coupled to a the midpoint node between the topside and bottomside transistors of the first half-bridge circuit; and a diode having an anode coupled to a second terminal of the bootstrap capacitor and a cathode coupled to a control terminal of the reverse battery protection transistor.

Abstract: An IC driver includes a resistor detector to detect whether at least a threshold resistance is present between a pin of the IC driver and the gate of an IGBT. The resistor detector can include a comparator that compares a voltage at the collector of the IGBT to a threshold reference voltage (e.g., ground). In response to drive signals of the IC driver being switched off, a parasitic inductance causes a voltage drop at the emitter of the IGBT, and a commensurate voltage drop at the IGBT collector. If the resistance between the IC driver pin and the IGBT gate is lower than a specified level, the voltage drop at the IGBT collector will be such that the collector voltage falls below the threshold reference voltage. In response, the comparator asserts a signal indicating a fault.

Abstract: A segmented driver including at least one drive pin and a sense pin, a driver circuit, a comparator, and a controller. The driver circuit activates a selected drive level between the drive pins and a reference node. The comparator compares a voltage of the sense pin with a threshold voltage and provides a threshold indication when the voltage of the sense pin reaches the threshold voltage. The controller commands the driver circuit to activate a first drive level in response to an off indication, and commands the driver circuit to switch to a second, lower drive level in response to the threshold indication. The driver circuit may be implemented using low resistive current devices. Multiple drive pins may be included, each for selectively activating a corresponding drive path to adjust drive level. The threshold voltage may be set using a current source and resistor, and may be adjusted for temperature.

Abstract: Operation of an insulated gate bipolar transistor (IGBT) is monitored by an apparatus that has a capacitor connected between a collector of the IGBT and an input node. A processing circuit, coupled to the input node, responds to current flowing through the capacitor by providing an indication whether a voltage level at the collector is changing and the rate of that change. The processing circuit also employs the capacitor current to provide an output voltage that indicates the voltage at the IGBT collector.

Abstract: A circuit performs a method for controlling turn-off of a semiconductor switching element. The method includes determining at least one operating parameter for the semiconductor switching element during an operating cycle and determining a gate discharge current based on the at least one operating parameter. The method further includes supplying the gate discharge current to a gate of the semiconductor switching element during a subsequent operating cycle to turn off the semiconductor switching element.

Abstract: A circuit is configured for providing reverse battery protection. The circuit includes a load driver circuit having at least a first half-bridge circuit with topside and bottomside transistors coupled at a midpoint node by a first current terminal of both the topside and bottomside transistors. A second current terminal of the bottomside transistor is coupled to a voltage common node. The circuit also includes: a reverse battery protection transistor having a first current terminal coupled to a battery supply node and a second current terminal coupled to a second current terminal of the topside transistor; a bootstrap capacitor having a first terminal coupled to a the midpoint node between the topside and bottomside transistors of the first half-bridge circuit; and a diode having an anode coupled to a second terminal of the bootstrap capacitor and a cathode coupled to a control terminal of the reverse battery protection transistor.

Abstract: A circuit performs a method for controlling turn-off of a semiconductor switching element. The method includes determining at least one operating parameter for the semiconductor switching element during an operating cycle and determining a gate discharge current based on the at least one operating parameter. The method further includes supplying the gate discharge current to a gate of the semiconductor switching element during a subsequent operating cycle to turn off the semiconductor switching element.

Abstract: Apparatus, systems, and methods are provided for protecting a switching device using a gate driver device. An exemplary gate driver system includes an interface for coupling to a switching device, a desaturation detection arrangement coupled to the interface to detect a desaturation condition based on an electrical characteristic at the interface, and a deactivation arrangement coupled to the interface to deactivate the switching device in a manner that is influenced by the electrical characteristic at the interface. In one embodiment, the switching device is deactivated by providing a deactivation current to a control terminal of the switching device and adjusting the deactivation current based on an electrical characteristic at the interface.

Abstract: Apparatus, systems, and methods are provided for protecting a switching device using a gate driver device. An exemplary gate driver system includes an interface for coupling to a switching device, a desaturation detection arrangement coupled to the interface to detect a desaturation condition based on an electrical characteristic at the interface, and a deactivation arrangement coupled to the interface to deactivate the switching device in a manner that is influenced by the electrical characteristic at the interface. In one embodiment, the switching device is deactivated by providing a deactivation current to a control terminal of the switching device and adjusting the deactivation current based on an electrical characteristic at the interface.

Abstract: A circuit and method for providing closed loop control using constant current switching techniques is disclosed herein. By controlling the current supplied to high intensity light emitting diodes (LEDs) using the techniques and circuits described, high intensity LEDs can be operated at or near their maximum capacity without danger of overloading the LEDs, and without using excess amounts of current. A circuit as described herein, has multiple high side switches, each of which is connected to an LED array. The LED arrays are in turn connected through an inductor to a current switching control section that switches current to ground, or recirculates the current to maintain LED current flow within a desired range.

Abstract: A circuit and method for providing closed loop control using constant current switching techniques is disclosed herein. By controlling the current supplied to high intensity light emitting diodes (LEDs) using the techniques and circuits described, high intensity LEDs can be operated at or near their maximum capacity without danger of overloading the LEDs, and without using excess amounts of current. A circuit as described herein, has multiple high side switches, each of which is connected to an LED array. The LED arrays are in turn connected through an inductor to a current switching control section that switches current to ground, or recirculates the current to maintain LED current flow within a desired range.