The UCC256301 is a fully featured LLC controller with integrated high-voltage gatedriver. It has been designed to pair with a PFC stage to provide a complete power system using aminimum of external components. The resulting power system is designed to meet the most stringentrequirements for standby power without the need for a separate standby power converter, and withPFC stage running all the time. UCC256301 includes a range of features designed to make LLCconverter operation well controlled and robust. This device aims to unburden the LLC designer andallow mainstream applications to benefit from efficiency advantages of the LLC topology.
UCC256301 uses hybrid hysteretic control to provide best in class line and load transientresponse. The control effort is approximately linear proportional to average input current in onecycle. The control makes the open loop transfer function a first order system so that it’s veryeasy to compensate. The system is always stable with proper frequency compensation.
UCC256301 provides a high efficient burst mode with consistent burst power level duringeach burst on cycle. The burst power level is programmable and adaptively changes with inputvoltage, making the optimization of efficiency very easy.