Patent ID: 8018210
Filing Date: 2011-09-13
Classification: H02M

Abstract:
1. A voltage converting circuit, comprising: a power stage, receiving an input voltage, and outputting the input voltage according to a duty cycle in internal of the power stage; a filter, receiving the input voltage output from the power stage to convert the input voltage into a current, and filtering the current to obtain an output voltage; a first feedback unit, receiving a reference voltage and the output voltage, and amplifying a difference between the reference voltage and the output voltage to obtain an error voltage; a second feedback unit, receiving the output voltage, and performing a quadratic differential operation and an integration operation to the output voltage to obtain a sensing voltage; and a comparator, comparing the error voltage and the sensing voltage, and outputting a comparing result to the power stage, so as to adjust a duty ratio of the duty cycle, wherein a ripple of the output voltage is linearly proportional to a ripple of the current, and a direct current (DC) divided voltage level of the output voltage is substantially equal to the reference voltage.