OUTPUT CURRENT ESTMATING METHOD AND POWER SUPPLY DEVICE USING THE SAME

摘要

A power supply device comprises a power switch; a rectification diode rectifying a current supplied upon switching of the power switch, and generating an output current; a switch control circuit generating a power estimating voltage corresponding to the output current by using a detection sensing voltage and a compensation discharge period corresponding to the sensing voltage along a switch current flowing through the power switch. The compensation discharge period is a period from a peak point of a discharge current flowing through the rectification diode to the point that the discharge current becomes zero.