| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a pulse width modulation circuit capable of utilizing a period as a temporal reference irrespective of the period of a triangle wave signal being varied discretely. <P>SOLUTION: The circuit includes triangle wave producing means (11) for producing the triangle wave signal having a constant amplitude and a period to be defined by a charging and discharging current of a capacitor (C<SB>T</SB>), current modulating means (13) for making the charging and discharging current of the capacitor (C<SB>T</SB>) changed discretely from a reference current value by a timing to be synchronized to the triangle wave signal, and comparing means (12) for producing a pulse width modulation signal by comparing the triangle wave signal with a modulated signal. The current modulating means (13) is to be configured so as to assign discrete variation components each having an equal value relating to one hand and the other hand of period among continuing two periods of the triangle wave signal, and to add and subtract the discrete variation components to and from the respective reference current values in the one hand and the other hand of periods. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
