| 摘要 |
PURPOSE:To prevent the occurrence of the offset at a driving body control signal by comparing and processing the value of a counter counting a reference clock by the period of the servo signal with the value of the counter circulating and counting by the constant period. CONSTITUTION:A signal for servo supplied to a terminal 24 is supplied to a pulse generating circuit 31, a counter 33 counts a clock from a reference clock generating circuit 32 by the period of the output pulse of the circuit 31 and the lower order four bits of the counted value are latched by a latch circuit 40. A counter 59 circulates and counts the clock of the circuit 32 at the constant period and the output is outputted to a comparing circuit 55. At the circuit 55, comparing is executed with the output of FF 41-43, a PWM modulating signal is generated to the comparing output and an output circuit 68 is driven by the signal and the output of the highest order FF 44 of the circuit 40. To the circuit 68, a reference voltage Vref, a voltage V higher than this and a grounding are supplied by the output of the circuit 55 and the FF 44, the voltage V or the grounding are selected, the output period is controlled and the signal to control the driving quantity of the driving body is outputted from a terminal 71.
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