Allegro Microsystems, LLC

Christy Looby

James McIntosh

Robert Douglas Christie

Colin Hall

An interface circuit, comprising: I/O circuitry configured to couple one or more first terminals with one or more second terminals; a voltage regulator configured to power the I/O circuitry; a restrictor element that is disposed between the voltage regulator and the I/O circuitry, the restrictor element being disposed on a circuit path that connects the voltage regulator to the I/O circuitry, the restrictor element being configured to open the circuit path and disconnect the voltage regulator from the I/O circuitry when an electrical current that is being supplied to the I/O circuitry exceeds a threshold; and a voltage suppressor that is disposed on the circuit path that connects the voltage regulator to the I/O circuitry, the voltage suppressor being disposed between the restrictor element and the I/O circuitry, the voltage suppressor being configured to limit, to a first voltage value, a voltage that is input into the I/O circuitry.

Interface for high-voltage applications

An isolation switch driver includes a control circuit to control conduction of an isolation switch and a voltage monitor circuit to monitor a control voltage coupled to the isolation switch and to generate a fault indication if the control voltage is less than a predetermined threshold. The isolator driver can drive an isolation switch coupled between a bridge network and a motor in a motor control system. The monitor circuit can monitor a voltage between a gate terminal and a source terminal of the isolation switch and include a resistive element coupled between the gate terminal and the source terminal to generate a current proportional to the VGS voltage, a current mirror to shift a level of the current to a reference potential, and a comparator to compare the level-shifted current to a threshold current.

Circuits and techniques for voltage monitoring of a solid-state isolator

A method for signaling between a controller and a driver includes receiving, at a pin of the driver coupled to the controller, a command signal generated by the controller and generating, by the driver at the pin coupled to the controller, a fault signal indicating a fault condition. The driver can be configured to drive a switch and the command signal can be configured to cause the driver to open the switch when the command signal is in a first state and to close the switch when the command signal is in a second state. The command signal being in the first state may correspond to the command signal having a voltage level above a first predetermined threshold and the command signal being in the second state may correspond to the command signal having a voltage level below a second predetermined threshold.

Circuits and techniques for signaling between devices

An electronic circuit for driving an electronic switch includes a first voltage terminal coupled to receive a first voltage from a power supply and a second voltage terminal coupled to receive a second voltage from the power supply. A driver circuit is configured to drive the voltage at a control terminal of the electronic switch to an intermediate voltage level in order to turn on the electronic switch during a high or normal voltage condition. A clamp circuit is configured to clamp the voltage at the control terminal of the electronic switch to the second voltage terminal in order to turn on the electronic switch during a low voltage condition, so that the electronic switch can enhance power provided to a load during the low voltage condition. A low voltage detection circuit detects the low voltage condition and provides a signal to activate the clamp circuit.

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Edinburgh, United Kingdom

Christy Looby