Texas Instruments Corporation

Mandy Barsilai

David Hernandez

Mark Stephen Toth

A method, apparatus and a system for a Linear Resonant Actuator (LRA) real time impedance tracking. The method includes extracting the Back Electro-Motive Force (BEMF) voltage from a driver's load current by determining a current multiplying factor utilizing a Least Mean Square (LMS) algorithm and introducing an error function to control the gain of the load current and isolate the BEMF.

Method and apparatus for LRA real time impedance tracking and BEMF extraction

Disclosed examples include methods and circuits to drive a haptic actuator, in which a single input signal from a host device has a first state representing a command to drive the actuator and a second state representing a command to stop the actuator. A control circuit provides a drive control signal to a driver circuit to drive the haptic actuator in response to the control signal transitioning to the first state, and to stop the haptic actuator in response to the control signal transitioning to the second state. A timer circuit places the circuit in a low power mode a predetermined time after the control signal transitions to the second state, or the control circuit places the circuit in the low power mode in response to a feedback signal indicating that the actuator has reached a stopped condition.

Integrated circuit with single wire haptic vibration control and selective open loop operation

A system includes a controller to control movement of a linear resonant actuator (LRA). The system includes a monitor in the controller to monitor a back electromotive force (BEMF) signal from the LRA representing the movement of the LRA. The monitor generates an indicator that indicates whether or not movement of the LRA has occurred. A primary loop module in the controller controls acceleration and braking of the LRA based on the monitored BEMF signal if the indicator from the monitor indicates that LRA movement has occurred. An alternate cycle module in the controller pushes the LRA at a predetermined frequency if the indicator from the monitor indicates that LRA movement has not occurred. The push is employed to move the LRA when the BEMF signal is undetectable by the monitor with respect to a predetermined threshold.

Adaptive linear resonance actuator controller

Circuits and methods for reading an OTP memory cell with improved reliability. To read a first OTP memory cell, a first current amount generated by a second, programmed, OTP memory cell is received. A second current amount generated by a third, unprogrammed, OTP memory cell is received. Current generated by the first OTP memory cell is sunk. The amount of current sunk from the first OTP memory cell is equal to a sum of a third current amount that is proportional to the first current amount plus a fourth current amount that is proportional to the second current amount. While sinking said current from the first OTP memory cell a voltage at a current output of the first OTP memory cell is compared to a threshold voltage.

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Richardson, TX, United States of America

Mandy Barsilai