Patent ID: 7154238

Claim:
A semiconductor integrated circuit device including a motor driving control apparatus which drives a brushless motor that includes coils corresponding to a plurality of phases based on Hall signals showing rotor positions, the motor diving control apparatus comprising: an amplitude regulation circuit which (a) includes variable gain amplifiers that are operable to amplify the Hall signals in a one-to-one correspondence and output the amplified signals, and (b) is operable to regulate each of the Hall signals at a constant amplitude and output the regulated signals, by controlling a gain of each of the variable gain amplifiers based on a difference in level between an amplified signal having a highest level and an amplified signal having a lowest level out of the amplified signals; a reference signal generation unit operable to generate a reference signal showing a voltage or current to be supplied to a coil corresponding to each of the plurality of phases, from the regulated signals; and a driving circuit operable to drive the coil corresponding to each of the plurality of phases based on the reference signal.