Mediatek Corporation

Mediatek Incorporation

Chao-Lung Tsai

Wen-Yi Wu

Chi-Kwong Ho

Chang-long Wu

Chang-Long Wu

An adaptive frequency detector used in a phase locked loop for detecting a frequency difference between an input signal and an output clock generated from an oscillator of the phase locked loop includes: a frequency comparator for generating an up signal or a down signal according to the frequency difference between the input signal and the output clock; and a pulse controller coupled to the frequency comparator for generating a charge signal based on the up signal or generating a discharge signal based on the down signal. The pulse controller dynamically adjusts the pulse width of the charge signal or the pulse width of the discharge signal.

Adaptive frequency detector of phase locked loop

A motor control system comprises a motor controller and a clamp apparatus and is used for controlling a motor apparatus. The motor controller is used for generating a motor control output according to a reference signal and a feedback signal from the motor apparatus. The clamp apparatus is used for receiving the motor control output and has a clamp function for clamping the motor control output. The clamp apparatus determines whether the clamp function should be activated to clamp the motor control output within an acceptable clamp range according to at least one motor stability signal. When the motor stability signal indicates that the motor apparatus has been in a stable state, the clamp apparatus clamps the motor control output from the motor controller in the acceptable clamp range, so as to avoid an abnormal motor control output resulting from external sudden change.

Motor control system having output clamp function and method of the same

The present invention provides a motor control system and method thereof. The motor control system comprises a motor controller and a compensation device. The motor controller is used for generating a motor control output according to a reference signal and a first signal. The compensation device is used for generating a compensated motor control output according to the motor control output and a second signal. Moreover, the compensation device utilizes the compensated motor control output to reduce the steady-state phase error between the first signal and the reference signal.

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Hsin-Chu, Taiwan

Chao-Lung Tsai