Motor driving circuit

摘要

A motor driving circuit may include a timing detection circuit configured to receive a signal that corresponds to the Hall signal output from the Hall sensor, and to generate a timing signal which is asserted at a predetermined timing in every cycle of the Hall signal. The timing detection circuit may include a counter configured to perform a counting operation according to a clock signal; a reset unit configured to reset a count value of the counter for every cycle of the counter, to a value obtained by multiplying the count value obtained immediately before the reset operation by a negative coefficient; and a comparison unit configured to assert the timing signal at every timing at which there is a zero-crossing in the value of the counter.

主权项

1. A motor driving circuit configured to receive a Hall signal, which comprises a first signal and a second signal that are complementary, from a Hall sensor, and to drive a motor, the motor driving circuit comprising:
a first A/D converter and a second A/D converter respectively configured to perform analog/digital conversion of the first signal and the second signal of the Hall signal so as to generate a third signal and a fourth signal in the form of digital signals; a differential conversion circuit configured to generate a fifth signal in the form of a single-ended signal that corresponds to the difference between the third signal and the fourth signal; an offset correction circuit configured to correct offset of the fifth signal so as to generate a sixth signal; an amplitude control circuit configured to stabilize the amplitude of the sixth signal to a predetermined target value, and to generate the absolute value of the resulting value, so as to generate a seventh signal; a control signal generating unit configured to generate a control signal based upon the seventh signal; a driver circuit configured to drive the motor according to the control signal; and a timing detection circuit configured to receive a signal that corresponds to the Hall signal output from the Hall sensor, and to generate a timing signal which is asserted at a predetermined timing in every cycle of the Hall signal, the timing detection circuit comprising:
a counter configured to perform a counting operation according to a clock signal;a reset unit configured to reset a count value of the counter for every cycle of the counter, to a value obtained by multiplying the count value obtained immediately before the reset operation by a negative coefficient; anda comparison unit configured to assert the timing signal at every timing at which there is a zero-crossing in the value of the counter, wherein the amplitude control circuit sets the value of the seventh signal for the amplitude of the seventh signal at a timing at which the timing signal is asserted.