DC-DC converter utilizing a modified Schmitt trigger circuit and method of modulating a pulse width

A DC-DC converter comprising:

• an amplifier configured to amplify a difference between a reference signal and a first feedback signal to generate a first signal;
• a comparator configured to compare a second feedback signal with the first signal to generate a second signal;
• a switch driver configured to generate a first switching signal and a second switching signal in response to the second signal;
• a power switch configured to transfer an input signal to a first output node in response to the first switching signal and the second switching signal, and configured to generate a pulse width modulated signal of which a pulse width and a frequency are varied, wherein the pulse width modulated signal is provided to the first output node;
• a filter configured to generate a direct current output voltage signal in response to the pulse width modulated signal, wherein the direct current output voltage signal is provided to a second output node;
• a negative feedback circuit configured to generate the first feedback signal in response to the direct current output voltage signal;
• and
• a positive feedback circuit configured to generate the second feedback signal oscillated in response to the pulse width modulated signal.

A DC-DC converter comprising:

• an amplifier configured to amplify a difference between a reference signal and a first feedback signal to generate a first signal;
• a comparator configured to compare a second feedback signal with the first signal to generate a second signal;
• an anti-overlap circuit configured to generate a first pulse signal and a second pulse signal in response to the second signal, the second pulse signal having a second pulse width wider than a first pulse width of the first pulse signal;
• a switch driver configured to generate a first switching signal and a second switching signal in response to the first pulse signal and the second pulse signal;
• a power switch configured to transfer an input signal to a first output node in response to the first switching signal and the second switching signal, and configured to generate a pulse width modulated signal of which a pulse width and a frequency are varied, wherein the pulse width modulated signal is provided to the first output node;
• a filter configured to generate a direct current output voltage signal in response to the pulse width modulated signal, wherein the direct current output voltage signal is provided to a second output node;
• a negative feedback circuit configured to generate the first feedback signal in response to the direct current output voltage signal;
• and
• a positive feedback circuit configured to generate the second feedback signal oscillated in response to the pulse width modulated signal.

A method of modulating a pulse width, comprising:

• positively feeding back a pulse width modulated signal to generate an oscillated signal;
• negatively feeding back a direct current output signal;
• amplifying a difference between the negatively fed-back direct current output signal and a reference signal to output a first signal;
• comparing the first signal with the oscillated signal to generate a first switching signal and a second switching signal;
• amplifying a difference between the negatively fed-back direct current output signal and the reference signal, comparing the oscillated signal with the reference signal and generating the first switching signal and the second switching signal, wherein the direct current output signal follows the reference signal;
• transferring an input signal to a first output node in response to the first switching signal and the second switching signal to generate a pulse width modulated signal of which a pulse width and a frequency are varied at the first output node;
• and
• generating a direct current output voltage signal at a second output node in response to the pulse width modulated signal.