| 摘要 |
PROBLEM TO BE SOLVED: To provide a pulse width modulation circuit of a wide band and a high resolution, for which power consumption is reduced while a circuit scale is kept suppressed. SOLUTION: High-order PWM signals for which basic PWM signals corresponding to the logic of digital signals S15-S8 are generated in a high-order PWM generator 12 and are delayed in a dummy multiplexer 135 and low-order PWM signals for which the output of the even-numbered stages of delay inverters 133_1 to 133_255 is inputted to a multiplexer 134 and selection is made by low-order digital signals S7-S1 are inputted to a PWM composition circuit 136, and a PWM pulse is generated by a value indicated by the high-order PWM signals and a value indicated by the low-order PWM signals. Also, the power supply voltage VPWM of a PWM power supply circuit 15 is adjusted corresponding to the speed of signals detected in a speed detection circuit 137. COPYRIGHT: (C)2009,JPO&INPIT
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