US Patent 7109769 PWM signal generator

A PWM signal generator comprises a pulse width indication signal generator outputting a pulse width indication signal, and a pulse width adjustment portion receiving the pulse width indication signal. The pulse width adjustment portion outputs an adjusted pulse width data which corresponds to the pulse width indication signal when the pulse width indicated by the pulse width indication signal is equal to or wider than a predetermined width. The pulse width adjustment portion accumulates the pulse width indicated by the pulse width indication signal when the pulse width indicated by the pulse width indication signal is narrower than the predetermined width. The pulse width adjustment portion outputs the adjusted pulse width data which corresponds to a sum data of the pulse width accumulated in the pulse width adjustment portion when the sum of the pulse width becomes equal to or wider than the predetermined width.