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: 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: 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: A Controller Area Network (CAN) node consists of a high-powered microcontroller, a low standby power regulator, a CAN bus transceiver, and a minimal CAN message buffer for storing received messages. Low power standby operation allows for the controller to power off, while the transceiver and regulator are operated in standby. The transceiver/regulator will enter run mode after the first symbol of a received CAN message is validated off the bus. As the original CAN message is received, it is buffered in the message buffer and, after stored, a status register is set to indicate the full message has been received. Once the controller has stabilized out of a wake-up mode, it retrieves the stored message and acts accordingly. The CAN message buffer is coupled to the controller by an system packet interface (SPI) interface for transmission of a controller wake-up command and retrieval of a buffered message.

Abstract: A squib ignitor circuit (20,40) reduces the probability of an accidental airbag deployment to greatly increase the safety of an automobile. A squib (24,28,44) operates at a voltage significantly higher than the squib ignitor circuit (20,40) to produce heat sufficient to ignite pyrotechnic material. Thus, a short condition to the squib (24,28,44) does not produce an inadvertent airbag deployment. The squib ignitor circuit (20,40) forms a conductive path through an inductor (23,43) via a first transistor (21,41) and a second transistor (22,42). The inductor (23,43) stores energy. The inductor (23,43) produces a voltage substantially greater than the voltage powering the squib ignitor circuit (20,40) when the conductive path is broken. The inductor (23,43) releases the stored energy to the squib (24,28,44) generating heat. A sequence (more than one time) of storing energy and releasing energy by the inductor (23,43) is required to generate heat sufficient to ignite pyrotechnic material by the squib (24,28,44).

Abstract: A voltage conversion circuit is responsive to a pulse-width modulated control signal for alternately enabling the gates of first and second field effect transistors which converts a high voltage input signal to a low voltage output signal. A first state of the control signal passes the high voltage input signal through the first transistor to charge a filter, while a second state of the control signal blocks the high voltage input signal from the filter. The second state of the control signal also sources current through the second transistor to the filter to rectify the low voltage output signal. The first and second transistors have non-overlapping conduction periods.

Abstract: A relay-less drive circuit for an inductive load preferably uses a transistor switch to couple the load to a battery, and provides a path for recirculating current around the load, which path includes a recirculating diode coupled in series with another transistor switch, such as an FET. the FET's drain and source terminals are connected to the recirculating diode, and the FET is biased, such that the FET is on when the battery is connected to the load with its nominal polarity, and the FET is off when the polarity of the battery is reversed.