Patent ID: 8350504

Claim:
A brushless DC motor driving system, comprising a parameter generator with its input terminals being connected to a speed control signal and a DC reference voltage, which outputs a speed parameter voltage to an input terminal of a feedback comparator, another input terminal of said feedback comparator being connected to a sensing voltage for outputting a reset signal to an input terminal of a S-R Flip-Flop, another input terminal of said S-R Flip-Flop being connected to an output set trigger signal of a frequency generator, an output digital signal of said S-R Flip-Flop being inputted to a duty cycle generator, an output DC level modulation voltage of said duty cycle generator and three-phase Hall voltage signals and triangular carrier frequency signal of said frequency generator being connected to a 180 degree phase generator which generates three-phase PWM control signals that are connected to an input terminal of a logic control circuit, another input terminal of said logic control circuit being connected to said digital signal, and three-phase PWM driving signals outputted by said logic control circuit being connected to a driving circuit ( 506 ), wherein the characteristic of said brushless DC motor driving system lies in that: said output digital signal of said S-R Flip-Flop is used to synchronously adjust said PWM driving signals synthesized from said duty cycle generator and said logic control circuit.