Patent ID: 7639055
Filing Date: 2009-12-29
Classification: H03K

Abstract:
1. A PWM signal generator comprising: an oscillator circuit configured to output an oscillator signal; a comparator circuit configured to receive said oscillator signal from said oscillator circuit and a reference signal, and further configured to output an output signal of a pulse train, which is level-inverted according to a magnitude relation between a level of said oscillator signal and a level of said reference signal, as a PWM signal for pulse width modulation control; and a level-inversion inhibiting circuit configured to inhibit level-inversion of said output signal, until a time before said output signal is subsequently level-inverted at a proper time according to a desired duty ratio of said PWM signal after said output signal is level-inverted, by changing, irrespective of a signal level of one of said oscillator signal and said reference signal, a level to be compared with a level of the other signal by said comparator circuit, so that said output signal is not level-inverted.