Voltage converter and power management device including the same

Abstract

A voltage converter includes a converting circuit having an inductor connected to a switching node, a first switch element connected between the switching node and a ground voltage, and a second switch element connected between the switching node and an output node; and a switching control circuit configured to adjust a feedback voltage divided from an output voltage of the output node based on a current state of the inductor, and configured to generate switching control signals for charging the inductor with an input voltage and discharging a voltage charged in the inductor, based on a sensing signal based on a current of the inductor and the adjusted feedback voltage.

What is claimed is: 
     
         1 . A voltage converter comprising:
 a converting circuit including an inductor connected to a switching node, a first switch element connected between the switching node and a ground voltage, and a second switch element connected between the switching node and an output node, the first switch element and the second switch element configured to switch for charging the inductor with an input voltage and discharging a voltage charged to the inductor; and   a switching control circuit configured to generate switching control signals for controlling the first switch element and the second switch element,   the switching control circuit including a ripple injection circuit configured to generate a ripple injection voltage having the same phase as a current of the inductor using an output voltage of the output node and the switching control signals,   the switching control circuit further configured to adjust a feedback voltage derived from the output node using the ripple injection voltage, and perform a first comparison based on the adjusted feedback voltage and a reference voltage to generate the switching control signals.   
     
     
         2 . The voltage converter of  claim 1 , wherein the switching control circuit is configured to
 sum the feedback voltage and the ripple injection voltage from which a DC component is removed,   performing a second comparison based on the summed voltage and the reference voltage, and   generate at least one of the switching control signals, based on a result of the second comparison and a sensing signal based on the current of the inductor.   
     
     
         3 . The voltage converter of  claim 1 , wherein the switching control circuit further includes an on-time control circuit configured to
 perform a second comparison based on the DC component and a ramp voltage generated from the output voltage, and   generate an on-time control signal for limiting a charging time of the inductor based on a result of the second comparison.   
     
     
         4 . The voltage converter of  claim 3 , wherein an on-time period controlled by the on-time control signal is proportional to a duty ratio of a reverse phase voltage to the voltage of the switching node.