LNK6406D LinkSwitch™3 AC/DC Converter Power Integrations LNK6406D LinkSwitch™3 AC/DC Converter simplifies low power CV/CC charger designs by eliminating the optocoupler and secondary circuitry. LinkSwitch™ introduces a revolutionary control technique that provides accurate output voltage and regulates the flow of current. This device has a 725V power MOSFET, a novel ON/OFF control state machine and a high voltage switched current source. LinkSwitch™ compensates for transformer inductance tolerances, input line voltage variations and cable voltage drop. This IC has a programmable switching frequency of up to 85kHz to reduce transformer size.