Texas Instruments Corporation

National Semiconductor Corporation

Ganapathi Hegde

Venkata Pavan Mahankali

Prasad Kulkarni

Sameer Pradeep Kulkarni

Krushal Shah

Mayank Garg

Krishnamurthy Ganapathi Shankar

Ashish Ojha

Priyank Anand

Siddhartha Gopal Krishna

Luis Eduardo Ossa

Sivabalan Mohan

V V Shyam Prasad

Vashist Bist

A motor control system operable to control a motor includes a motor control circuit and an inverter circuit connected to the motor control circuit and configured to connect to the motor at phase output terminals. The inverter circuit, in response to one or more output control signals indicating a deceleration instruction from the motor control circuit, implements a multi-state deceleration sequence for at least one commutation state of a commutation scheme of the motor.

Fast deceleration of PMSM and BLDC motors using recirculation braking

A motor controller that is operable to control a motor includes drive current generation circuitry having an output coupled to the motor. The motor controller further includes a velocity control path. The velocity control path includes angular velocity estimation circuitry having an input adapted to be coupled to the motor, a velocity comparator having first input coupled to a target velocity input and a second input coupled to an output of the angular velocity estimation circuitry, and an adaptive velocity controller having a first input coupled to an output of the velocity comparator and having an output coupled to a first input of the drive current generation circuitry. The motor controller further includes controller parameter determination circuitry having a first input coupled to the output of the angular velocity estimation circuitry and having an output coupled to a second input of the adaptive velocity controller.

Motor controller and a method for controlling a motor

Described examples include a method that includes setting a reference isignal in a field-oriented control of a motor such that the field-oriented control modulates power from a power supply using a modulator to apply a torque on the motor that is opposite to a kinetic energy applied to the motor. The method also includes setting a reference isignal in the field-oriented control such that the motor current provided to the power supply is reduced.

Motor control with reduced back current during braking

A control circuit regulates the propagation delay of a field effect transistor (FET) before the FET transitions to the Miller region by applying a pre-charge current for a fixed duration to the gates of the FET. After the fixed duration, the current is reduced to a lower drive current level which is based on a desired output voltage slew rate. After the FET transitions to the Miller region, the output voltage slews down in accordance with the output voltage slew rate. By regulating the slew-rate of the output voltage in the Miller region and regulating the propagation delay of the FET prior to the Miller region, the control circuit reduces electromagnetic interference (EMI) caused by the switching of the FET, thereby improving electromagnetic compatibility (EMC) of switch mode driver systems without increasing the propagation delay of the FET.

Systems and methods for regulation of propagation delay in DC motor drivers

An apparatus for regulating a slew time of an output voltage of a motor driver system includes a gate current control circuit which has a first input coupled to receive a target slew time and a second input coupled to receive a slew time. The gate current control circuit provides an incremented gate current if the slew time is greater than the target slew time and provides a decremented gate current if the slew time is less than the target slew time. The apparatus includes a gate driver which has a first input coupled to receive a PWM signal and a second input coupled to receive the gate current. The gate driver provides a gate drive signal.

Systems and methods for regulating slew time of output voltage of DC motor drivers

Example systems and processes use three-phase vector mutual inductance analysis to detect zero-crossing (ZC) locations of back-electromotive force (BEMF) of an electric motor and to detect its commutation points during start-up or low-speed operation. For each sector of rotation of the rotor, two pairs of three-phase vectors are applied, along with current for the corresponding driving phase. The first pair is alternately applied to move the rotor, and the mutual inductances resulting from such application are compared to detect the zero-crossing (ZC) location in the BEMF of the electric motor in that sector. The second pair is then alternately applied within the same sector to continue to move the rotor, and the mutual inductances from such application are compared to detect the commutation point of the electric motor in that sector. The process may be repeated for each successive sector, changing the driving current at each new sector.

Inductance-based, high-torque start up of electric motor

A motor controller integrated circuit (IC) includes a storage device containing software, and a processor core. The processor core has an output adapted to be coupled to a motor. The processor core is configured to execute the software to operate the motor in an open-loop control, calculate first and second orthogonal components of a back electromotive force (BEMF), calculate a total BEMF value, and determine that the first orthogonal component is within a threshold of the total BEMF value. The processor core is further configured to, responsive to the first orthogonal component being within the threshold of the total BEMF value, operate the motor in a closed-loop control.

Automatic transition of motor controller from open-loop control to closed-loop control

A controller is adapted to be coupled to a brushless direct current (DC) motor and includes an analog-to-digital converter (ADC), a computing device, and a driver. The ADC is configured to receive an analog back electromotive force (BEMF) waveform from the brushless DC motor and sample the analog BEMF waveform to produce a digital BEMF waveform. The computing device is coupled to the ADC and is configured to receive the digital BEMF waveform and determine a position and a speed of the rotor based on the digital BEMF waveform. The driver is coupled to the ADC and the computing device and is configured to receive the position and the speed of the rotor and provide a drive signal based on the position and the speed of the rotor of the brushless DC motor.

Resynchronization of brushless DC motors

Example systems and processes compare sampled values of a floating phase voltage and/or outgoing phase current of an electric motor with a corresponding reference to identify a degauss time period. Post degauss time period identification, sampled values are compared with a threshold to identify a settling time period following the degauss time period. The threshold used to identify the settling time period depends on a slope of a floating phase voltage after the degauss time period, a modulation scheme being used, and a pulse width modulation ON/OFF state of the electric motor. When the threshold comparison test is not met, it is determined whether the slope of the floating phase voltage has inverted. Based on such processing, a back-electromotive force (BEMF) zero-crossing (ZC) is detected or estimated with respect to a floating phase voltage of the electric motor.

Degauss time detection in electric motors

A synchronous serial bus peripheral circuit includes a peripheral identification (ID) register and a state machine circuit. The state machine circuit is coupled to the peripheral ID register, and is configured to transmit a status value based on a peripheral ID field of data received via the receiver shift register equaling a value stored in the peripheral ID register.

Synchronous serial interface allowing communication with multiple peripheral devices using a single chip select

Example systems and processes control transition of an electric motor from open-loop operation to closed-loop operation by detecting zero-crossing (ZC) locations of the back-electromotive force (BEMF). The rotor angle of the electric motor is changed, e.g., by changing acceleration of the electric motor to correct a phase difference based on the detected ZC locations and an open-loop profile of the electric motor. Detected ZC locations may be used to identify ZC-detected-based commutation points, and each detected ZC location may be used to update a next commutation point. During the control process the open-loop profile is updated. Transition may occur when a set number of ZC-detection-based commutation points are sufficiently aligned with corresponding updated commutation points, or such alignment is maintained for at least one electrical cycle.

Operational transition control of a motor

A system includes: a motor having a stator and a rotor; and a pulse generation circuit coupled to the stator. The system also includes a motor controller coupled to the pulse generation circuit. The motor controller is configured to: determine inductance and resistance values of the motor based on timing parameters obtained during an initial position detection (IPD) interval; determine a rotor position based on the determined inductance and resistance values; and generate control signals for the pulse generation circuit based on the determined rotor position.

Motor resistance and inductance values from initial position detection timing parameters

A system includes a motor and a motor controller coupled to the motor. The motor controller includes a current sense circuit configured to: receive a first phase current sense measurement on a first measurement path; receive the first phase current sense measurement on a second measurement path; receive a second phase current measurement on the first measurement path; receive the second phase current on the second measurement path; average the first phase current sense measurement on the first measurement path with the first phase current sense measurement on the second path; and average the second phase current sense measurement on the first measurement path with the second phase current sense measurement on the second path.

Current sense circuit with alternating measurement paths

Systems and methods for a Dual Window Watchdog Timer (DWWDT) are described. In some embodiments, a method may include running a first counter in a first clock domain and a second counter in a second clock domain; generating an interrupt to a controller during a window open period, wherein the window open period begins in response to the first counter having reached a predetermined threshold; and at least one of: restarting the first counter if the controller restarts the second counter in response to the interrupt before the window open period ends; or issuing a system reset if the controller does not restart the second counter in response to the interrupt before the window open period ends.

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Bengaluru, India

Ganapathi Hegde