Amplitude regulation circuit and method, and motor driving control apparatus and method

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 driving 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.

A semiconductor integrated circuit device including an amplitude regulation circuit which regulates a signal of each of a plurality of phases in a polyphase alternating signal at a constant amplitude, and outputs the regulated signal, the amplitude regulation circuit comprising:

• variable gain amplifiers corresponding one-to-one with the plurality of phases, each of the variable gain amplifiers being operable to amplify a signal of a corresponding phase using a gain controlled by a control signal, and output the amplified signal;
• a maximum detection unit operable to output a maximum signal, based on an amplified signal having a highest level out of amplified signals which are output from the variable gain amplifiers;
• a minimum detection unit operable to output a minimum signal, based on an amplified signal having a lowest level out of the amplified signals;
• and
• a control signal generation unit operable to output, to each of the variable gain amplifiers, a control signal for decreasing the gain when a difference between the maximum signal and the minimum signal is greater than a predetermined reference value, and a control signal for increasing the gain when the difference is no greater than the predetermined reference value.

A semiconductor integrated circuit device including an amplitude regulation circuit which regulates a signal of each of a plurality of phases in a polyphase alternating signal at a constant amplitude, and outputs the regulated signal, the amplitude regulation circuit comprising:

• variable gain amplifiers corresponding one-to-one with the plurality of phases, each of the variable gain amplifiers being operable to amplify a signal of a corresponding phase using a gain controlled by a control signal, and output the amplified signal;
• square units corresponding one-to-one with the plurality of phases, each of the square units being operable to square an amplified signal output from a variable gain amplifier of a corresponding phase, and output the squared signal;
• an addition unit operable to calculate a sum of squared signals output from the square units, and output the sum as a square sum signal;
• and
• a control signal generation unit operable to output, to each of the variable gain amplifiers, a control signal for decreasing the gain when the square sum signal is greater than a predetermined reference value, and a control signal for increasing the gain when the square sum signal is no greater than the predetermined reference value.