Patent ID: 8049448

Claim:
A control circuit for controlling a BLDC (brushless direct current) motor, comprising: a speed synthesizer, coupled to said BLDC motor for generating a speed-feedback signal in response to a plurality of speed-output signals of said BLDC motor; a torque synthesizer, coupled to said BLDC motor for generating a torque-feedback signal in response to a plurality of switching-current signals, wherein said switching-current signals are correlated to switching currents of said BLDC motor; a first programmable signal generator, generating a speed-reference signal; a second programmable signal generator, generating a torque-reference signal; a first error amplifier, coupled to receive said speed-feedback signal and said speed-reference signal for developing a speed-feedback loop and generating a speed-control signal; a second error amplifier, coupled to receive said torque-feedback signal and said torque-reference signal for developing a torque-feedback loop and generating a torque-control signal; and a PWM circuit, generating a PWM signal to drive said BLDC motor in response to said speed-control signal and/or said torque-control signal; wherein said speed-feedback signal and said torque-feedback signal are analog signals; and wherein a pulse width of said PWM signal is correlated to the level of said speed-control signal and/or the level of said torque-control signal.