Patent ID: 6546048
Filing Date: 2003-04-08
Classification: H02M,H03K

Abstract:
A pulse width modulation waveform generating circuit for generating 2n kinds of pulse width modulation signals having different pulse widths in accordance with a digital signal of n (n is an integer equal to or more than 2) bits, comprising;oscillating signal output means for having m (m is an odd number more than 2) pieces of first inverting means connected in series to each other, each of these first inverting means outputting an oscillating signal with a phase different from each other, the output of said first inverting means at the last stage of the series connected first inverting means being fed back to the input side of the first inverting means at the initial stage of the series connected first inverting means; selecting means for selecting one of the signals in accordance with each of the output signals of said m pieces of first inverting means connected in series, based on at least partial bits of said digital signal of n bits, and pulse generating means for generating said pulse width modulation signal having a pulse width in accordance with the signal selected by said selecting means.