Patent ID: 8569984

Claim:
A motor controller controlling a motor, comprising a thermal detector for detecting environmental temperature around the motor to dynamically determine a first reference voltage based on the detected environmental temperature; a first capacitor having a first terminal and a second terminal, wherein the first terminal is coupled to a second reference voltage; a first operational amplifier coupled to the second terminal of the first capacitor to receive a third reference voltage and compare the third reference voltage with the first reference voltage; a charging/discharging circuit charging/discharging the first capacitor based on a pulse width modulation (PWM) signal to change the third reference voltage; a flip-flop having a set terminal receiving a signal at an output terminal of the first operational amplifier, a reset terminal receiving a clock signal, and an output terminal coupled to the charging/discharging circuit to provide the charging/discharging circuit with the PWM signal; and a logic circuit coupled to the output terminal of the flip-flop to determine a duty cycle of a driving current of the motor based on the PWM signal.