Pulse generating circuit for driving DC motor

摘要

A pulse generating circuit for motor rotation of a direct current motor which is capable of pulse generation following the variation of the motor rotation condition and of stable ripple pulse generation. The pulse generating circuit for motor rotation includes a filter for varying a cut-off frequency fc by the signal from outside and for removing the noise based on the input signal from the direct current motor, a pulse forming circuit for forming the ripple pulse in accordance with the motor rotation of the direct current motor based on the output from the filter, a clock generating circuit for varying the cut-off frequency fc of the filter by providing the clock signal fCLK which is generated based on the rotational condition signal of the ripple pulse and the direct current motor to the filter, and a pulse correction circuit for generating the corrected ripple pulse when the frequency ratio between the ripple pulse and the clock signal fCLK is deviated.