Allegro Microsystems, LLC

Timothy Reynolds

Chengyi Jin

Chee-Kiong Ng

Robert J Stoddard

Christopher Alger

William Boyd Alcorn

Walter Kim

Thomas Rowan

Dennis Hwang

A motor drive circuit for driving an electric motor includes a plurality of driver circuits, each one of the plurality of driver circuit comprising a high side transistor coupled to a low side transistor in a half bridge arrangement, wherein each one of the high side transistors and each one of the low side transistors has a respective control node and respective first and second current passing nodes, wherein the second current passing node of each of the high side transistors is coupled to the first current passing node of a respective one of the low side transistors at a respective junction node, wherein each one of the plurality of driver circuits is operable to drive a respective current out of a respective junction node into a respective winding of the electric motor. The motor drive circuit further includes a capacitor coupled to the first current passing node of each one of the high side transistors, the capacitor operable to hold a capacitor voltage. The motor drive circuit further includes a power loss brake control circuit coupled to receive the capacitor voltage from the capacitor and operable to sense when a power supply voltage to the motor drive circuit is below a threshold voltage and, in a braking mode of operation, the high side transistors are off, and also in the braking mode of operation, when the power supply voltage is below the threshold voltage, the power loss brake control circuit is operable to generate at least one pulse signal having at least two state transitions and operable to communicate the at least one pulse signal to a respective at least one of the control nodes of a respective at least one of the low side transistors, resulting in on and off conditions of the at least one of the low side transistors, wherein the on condition of the at least one of the low side transistors results in the braking mode of operation during the on condition, and wherein the at least two state transitions results in a voltage boosting operation such that the capacitor voltage is a boosted voltage, the boosted voltage higher than a voltage that would be achieved without the at least two state transitions.

Electronic circuit for reducing rotation speed of an unpowered electric motor

A motor control system is presented. The motor control system includes a motor controller and a motor driver. The motor controller and motor driver are coupled by an interface which includes a conductor configured to carry both a motor speed control signal from the motor controller to the motor driver and a motor feedback signal from the motor driver to the motor controller. The motor controller provides a motor speed control signal to the motor driver and the motor driver provides a motor feedback signal to the motor controller.

Motor control system and interface

A motor driver includes at least two terminals suitable for being coupled to a motor controller and to receive a motor command signal and transmit a motor status signal when the motor driver is controlling a motor. A serial data communication circuit may be configured to send and receive serial data over the at least two terminals when the at least two terminals are idle.

System and method for serial communication by an electronic circuit

A motor control circuit and associated techniques can drive an electric motor in a start-up mode of operation followed by a normal mode of operation. The motor control circuit and techniques can receive a selection signal provided by a user that can select one of a plurality of sets of parameter values that determine characteristics of drive signals applied to the motor during the start-up mode of operation. The motor control circuit and associated techniques can synchronize operation between the start-up mode of operation and the normal mode of operation.

Electronic circuit and method for adjusting start-up characteristics of drive signals applied to an electric motor

Electronic circuit and method for synchronizing electric motor drive signals between a start-up mode of operation and a normal mode of operation

A motor control circuit and associated techniques can adjust a phase of a motor drive to keep a rotational reference position of an electric motor at the same relative phase as a zero current in a motor winding at different motor speeds and as the motor accelerates and decelerates. In some embodiments, a particular circuit and technique can be used to detect the zero current in the motor winding.

Electronic circuit and method for automatically adjusting a phase of a drive signal applied to an electric motor in accordance with a zero current detected in a winding of the electric motor

A motor control circuit and associated techniques detect a zero crossing of a current in a motor winding by detecting a reverse current in a half bridge circuit used to drive the motor winding.

Electronic circuit and method for detecting a zero current in a winding of an electric motor

An electronic circuit and an associated method used to drive an electric motor provide a user selectable relationship between rotational speed of the electric motor and phase advances of signals used to drive the electric motor. By selecting the relationship, efficiency of the electric motor drive can be improved.

Electronic circuit and method generating electric motor drive signals having phase advances in accordance with a user selected relationship between rotational speed of an electric motor and the phase advances

Growing community of inventors

Westborough, MA, United States of America

Timothy Reynolds