Patent ID: 8456118

Claim:
A motor driving circuit comprising: a cycle counter configured to generate a cycle signal which indicates, in the form of a digital value, the cycle of a Hall signal that indicates the position of a rotor of a motor to be driven; an up/down counter configured to repeatedly alternate between counting “up” and counting “down” between a bottom value and a peak value, wherein the counting up and the counting down respectively starts when detecting phase transitions that occur in the Hall signal, an output of the up/down counter is a digital value and has a trapezoidal waveform including a first sloping region corresponding to the counting up and a second sloping region corresponding to the counting down, and the slope of the first and the second sloping regions are set according to the cycle signal; a D/A converter configured to receive the output of the up/down counter, and to convert the output of the up/down counter into an analog voltage; and a driving unit configured to supply a driving voltage that corresponds to the analog voltage to the motor.