Current-mode control type dc-dc converter and control method therefor

A current-mode control type DC-DC converter to control an output voltage comprising:

• switching means turned on every time a clock signal is input thereto in predetermined cycles;
• inductor means supplied with electric current when the switching means is turned on;
• error amplifier means for outputting an error voltage that is generated by amplifying a difference between a predetermined reference voltage and a divided voltage that is generated by dividing the output voltage of the DC-DC converter;
• slope voltage generation means for generating a slope voltage by performing slope compensation on an inductor current;
• PWN comparing means for comparing the slope voltage with the error voltage and generate a reset pulse to turn off the switching means when the slope voltage reaches the error voltage;
• and
• slope voltage maintenance means for keeping the slope voltage at the ground voltage during a time period from when the reset pulse is generated to when a subsequent clock signal is generated.

A method for controlling a current-mode control type DC-DC converter comprising:

• turning on a switching transistor with a clock signal that is input thereto in predetermined cycles;
• supplying electric current to an inductor when the switching transistor is turned on;
• generating an error voltage by amplifying a difference between a predetermined reference voltage and a divided voltage that is generated by dividing the output voltage of the DC-DC converter;
• generating a slope voltage by performing slope compensation on an inductor current;
• comparing the slope voltage with the error voltage;
• generating a reset pulse to turn off the switching transistor when the slope voltage reaches the error voltage;
• and
• keeping the slope voltage at the ground voltage during a time period from when the reset pulse is generated to when a subsequent clock signal is generated.