Patent ID: 7301294

Claim:
A motor speed control integrated circuit which controls a rotational speed of a motor by controlling the amount of current flowing through a drive coil of the motor, the integrated circuit comprising: a first input terminal to have an analog speed-specifying signal in analog amount specifying the rotational speed of the motor input thereto; a second input terminal to have a digital speed-specifying signal in digital amount specifying the rotational speed of the motor input thereto; a reference voltage circuit that generates a reference voltage corresponding to the analog speed-specifying signal, when only the analog speed-specifying signal is input to the first input terminal, and that generates a reference voltage corresponding to the digital speed-specifying signal, when only the digital speed-specifying signal is input to the second input terminal, and that generates a reference voltage corresponding to the analog speed-specifying signal and the digital speed-specifying signal, when the analog speed-specifying signal and the digital speed-specifying signal are input to the first input terminal and the second input terminal, respectively; a comparator that compares a speed voltage corresponding to the actual rotational speed of the motor and the reference voltage; and a control signal generator that generates and outputs a control signal for controlling the amount of current flowing through the drive coil based on the comparing result of the comparator.