The LT8316 is a micropower, high voltage flyback controller. No opto-isolator is needed for regulation. The device samples the output voltage from the isolated flyback waveform appearing across a third winding on the transformer. Quasi-resonant boundary mode operation improves load regulation, reduces transformer size, and maintains high efficiency.At start-up, the LT8316 charges its INTVCCcapacitor via a high voltage current source. During normal operation, the current source turns off and the device draws its power from a third winding on the transformer minimizing standby power dissipation.The LT8316 operates from a wide range of input supply voltages and can deliver up to 100W of power. It is available in a thermally enhanced 20-pin TSSOP package with four pins removed for high-voltage spacing.APPLICATIONSIsolated Telecom, Automotive, Industrial, Medical Power SuppliesIsolated Off-Line Housekeeping Power SuppliesElectric Vehicles and Battery StacksMultioutput Isolated Power Supplies for Inverter Gate Drives