Prolific Technology Inc.

Richtek Technology Corporation

Kuang-Yao Cheng

Wei-Hsu Chang

Hung-Shou Nien

Yi-Chiang Fu

Tung-Chin Hsieh

An apparatus and method for use with a PMSM detect the fall time or the rise time and the fall time of a motor current in the PMSM under different voltage vectors when the PMSM is in start-up to determine an initial rotor position for the PMSM at standstill.

Initial rotor position detection for permanent magnet synchronous motors

A hybrid control circuit and method combine analog circuit and digital circuit to generate digital PWM signals for a multiphase DC-DC converter to generate an output voltage. For current balance control, analog current error signals are generated by the analog circuit from analog phase current signals of the multiphase DC-DC converter and then converted into digital current error signals for calculating the duties of each phase of the multiphase DC-DC converter. Therefore, fewer bit devices can be used to achieve precise current balance control and the size and cost of the circuit can be reduced.

Hybrid control circuit and method

After an AC motor generates a three-phase current, modulate the three-phase current to generate an original voltage space vector, and add three detecting vectors with a sum of zero after the original voltage space vector. While adding the three detecting vectors, sample the current to generate a sampling result. Then adjust the width of pulses generated by a pulse width modulator according to the sampling result.

To obtain the three-phase current via adjusting width of pulses with single DC-link current sensor

A method and a circuit for controlling a motor and a brushless motor using the same are provided. The brushless motor includes three phase coils, wherein the first terminals of all the phase coils are coupled to a common node. The method includes following steps: among the above-mentioned three phase coils, when there is no current flowing through the first phase coil of the above-mentioned three phase coils and a current flows from the second terminal of the second coil to the second terminal of the third phase coil, detecting the voltage at the second terminal of the first phase coil to be a first specific voltage; detecting the voltage drop of a DC sensing resistor to be a second specific voltage; and utilizing the first specific voltage, the second specific voltage and the DC voltage supplied to the motor to estimate zero crossing points for controlling the motor.

Method and circuit for controlling motor and brushless motor system using the same

A motor driver has a plurality of output circuits each having an upper side switch and a lower side switch connected in series for supplying a current to a motor. The motor driver includes a current detection resistor connected in series with the plurality of output circuits in common for detecting a current supplied to the plurality of output circuits, a position detection circuit for outputting a position signal corresponding to a position of a rotor of the motor, a current command generation circuit for generating a target current command signal based on the position signal and a predetermined phase angle in which a phase angle of the target current command signal is determined by the predetermined phase angle, and a space vector modulation based logic control circuit for commanding a plurality of output circuits that are set in a plurality of switches states for control of an electric motor.

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Taipei, Taiwan

Kuang-Yao Cheng