| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital/analog (D/A) converter for removing a higher harmonic wave component of a PWM (Pulse Width Modulation) with a simple configuration without requiring adjustment for determining a coefficient for generating an accurate distortion component. SOLUTION: A D/A converter comprises a DSM 103 for delta/sigma modulating a digital signal, a PWM 104 for outputting a pulse width modulation signal of a pulse width corresponding to a digital signal outputted from the DSM 103, and a distortion detector 102 for detecting a distortion component generated by the PWM 104. The distortion detector 102 comprises a delay controller 115 which receives a digital signal and corrects the phase, a DSM 113, a PWM 114, a subtractor 116 which subtracts output of the DSM 113 from output of the PWM 114 and outputs the subtraction result, and a subtractor 117 which subtracts an output signal of the subtractor 116 from an output signal of the delay controller 115. COPYRIGHT: (C)2009,JPO&INPIT
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