Patent ID: 9136787
Filing Date: 2015-09-15
Classification: G05B,H02P

Abstract:
1. An integrated circuit comprising: a motor current input voltage-to-current (VI) converter that receives a motor current sensor voltage from a motor and a reference voltage that generates an output current related to a motor's current; a motor current calibration VI converter that compensates for errors in the motor current input VI converter and generates a calibration output current based on the reference voltage, wherein the output current and the calibration output current are combined to form an estimate of the motor's current; a summing node, which receives the outputs of the motor current VI converter and the motor current calibration VI converter and sums the output current and the calibration output current; a stage amplifier that amplifies current from the summing node, wherein output from the stage amplifier is fed back to the motor current calibration VI converter and is fed to a back electromotive force (BEMF) stage, wherein the BEMF stage computes a BEMF voltage for the motor; the BEMF stage further comprising: a motor voltage input voltage-to-current (VI) converter that receives a motor voltage sensor voltage from the motor and a reference voltage that generates an output current related to the motor's voltage; a motor voltage calibration VI converter that compensates for errors in the motor voltage input VI converter and generates a calibration output current based on the reference voltage, wherein the output current and the calibration output current are combined to determine an estimate of the motor's voltage; and an input VI converter that receives the output from the stage amplifier and generates a current relating to the motor's current to enable computation of the motor's BEMF voltage.