Utilization of a multifunctional pin combining voltage sensing and zero current detection to control a switched-mode power converter

摘要

An embodiment of the invention relates to a power converter including an inductor coupled in series with a power switch and a resistor coupled to a winding of the inductor. Input and output power converter voltages including an input brownout condition or an output overvoltage condition are estimated, and the output voltage may be regulated, by sensing a current in the resistor. An input current waveform can thereby be controlled to replicate substantially the input voltage waveform. The controller adjusts an on time and terminates an off time of the power switch by sensing respectively a current and a change of current in the resistor. The controller may sense a current flowing in the resistor to select a line voltage range of the input voltage to the power converter. The controller may estimate an input current to the power converter employing the current flowing in the resistor.