초록 ▼

A pulse width modulation circuit includes an operation unit which generates a compensation signal based on the product of a deviation of an input signal from a first reference value and a deviation of a power supply voltage from a second reference. A level change unit changes the level of at least o

A pulse width modulation circuit includes an operation unit which generates a compensation signal based on the product of a deviation of an input signal from a first reference value and a deviation of a power supply voltage from a second reference. A level change unit changes the level of at least one of an error signal from an error amplifier and a reference wave signal generated by a reference wave signal generator in accordance with the compensation signal so that a relative level defined by a level difference between the error signal and the reference wave signal changes in accordance with the compensation signal. The pulse width modulation circuit also includes a unit for comparing the level of the error signal and the level of the reference wave signal having a changed relative level with each other and for generating a pulse width modulated signal based on a comparison result.

대표청구항 ▼

A pulse width modulation circuit comprising: error amplifier means for generating an error signal corresponding to a difference between an input signal and a compare signal; operation means for generating a compensation signal based on a product of a deviation of said input signal from a first refer

A pulse width modulation circuit comprising: error amplifier means for generating an error signal corresponding to a difference between an input signal and a compare signal; operation means for generating a compensation signal based on a product of a deviation of said input signal from a first reference value and a deviation of a power supply voltage from a second reference value; reference wave signal generating means for generating a reference wave signal having a fixed period and a fixed amplitude; level change means, operatively coupled to said error amplifier means and said reference wave signal generating means, for changing a level of at least one of said error signal and said reference wave signal in accordance with said compensation signal so that a relative level defined by a level difference between said error signal and said reference wave signal changes in accordance with said compensation signal; compare means, operatively coupled to said level change means, for comparing the level of the error signal and the level of said reference wave signal having a changed relative level with each other and for generating a pulse width modulated signal based on a comparison result; current supply means, coupled to said compare means, for supplying a load current based on a duty ratio of said pulse width modulated signal to a load; and load current detection means, operatively coupled to said error amplifier means, for detecting said load current passing through said load and for generating said compare signal based on a detected load current.