DER-260: 5V @ 300mA, 1.5W Out, 85 ~ 265VAC in

This report describes a universal input, 5 V, 300 mA non-isolated flyback power supply which is designed with LNK584DG device from the LinkZero-AX family of ICs. It contains the complete specification of the power supply, a detailed circuit diagram, the entire bill of materials required to build the supply, extensive documentation of the power transformer, along with test data and oscillographs of the most important electrical waveforms.

LinkZero-AX combines extremely low standby/Power-Down energy use with the industry’s lowest component count standby supply solution. Below 3 mW at 230 VAC in Power-Down (PD) mode meets IEC 62301 definition of zero power consumption and is immeasurable on most power meters. LinkZero-AX is set into Power-Down mode using an external signal to pull the FEEDBACK pin high for 2.5 ms. Such an external signal can be generated by a system micro controller or infrared controller. In Power-Down mode the BYPASS pin remains regulated allowing the LinkZero-AX to be woken up with a reset pulse to pull the BYPASS pin below a reset threshold (1.5 V). Ultra low system consumption is therefore achieved without needing to disconnect the input voltage with a relay.

LinkZero-AX is designed to be used in isolated or non-isolated converters. In either, the tightly specified FEEDBACK (FB) pin voltage reference enables universal input primary side regulated power supplies that cost-effectively replace unregulated linear transformer and other switched mode supplies. The start-up and operating power are derived directly from the DRAIN pin. The internal oscillator frequency is jittered to significantly reduce both quasi-peak and average EMI, minimizing filter cost.