Patent ID: 8362727

Claim:
A semiconductor integrated circuit device configured so as to control a synchronous motor that is to be coupled to said semiconductor integrated circuit device through an inverter, said semiconductor integrated circuit device comprising: a current reproducer that reproduces phase currents of the synchronous motor from at least one of a current flowing to the synchronous motor and a current supplied to the inverter each detected by the inverter and outputted to said semiconductor integrated circuit device; and a proportional-integral controller having an integral gain Ki, wherein the integral gain Ki is defined as a function of ω 1 , N, and L, where the ωl is a driving electric angular frequency of the synchronous motor, the N is an arbitrary integer, and the L is an inductance of the synchronous motor, wherein said semiconductor integrated circuit device adjusts a voltage output from the inverter based on the phase currents reproduced by said current reproducer, and wherein the function of ω 1 , N, and L is in accordance with an equation of Ki=(ω 1 ·N) 2 ·L.