SWITCHED-MODE POWER SUPPLY

摘要

Provided is a switched-mode power supply. The power supply includes: a DC voltage input terminal; a driver switching element connected to the input terminal; an inductor connected to the driver switching element; an output terminal connected to the inductor and outputting output voltage different from the input voltage; and an integrated circuit outputting control pulses used for on-off control of the driver switching element. The integrated circuit has: a ripple injection circuit adding a ripple component to a feedback voltage of the output voltage; a voltage comparator comparing the summed voltage with a predetermined voltage; and a control pulse generator generating the control pulse based on an output of the voltage comparator. The ripple injection circuit has an integrator outputting an integral of the voltage at the node between the driver switching element and the inductor, and a series RC circuit connected to the output end of the integrator.