The HR1200 integrates a digital PFC controller and a half-bridge resonant controller into a single chip. It uses very low power at no-load or ultra-light load, making it compliant with Energy Using Product Directive (EuP) Lot 6 and Code of Conduct Version 5 Tier 2 specifications.
The PFC of the HR1200 employs a patented average current control scheme, which can operate in CCM and DCM multi-mode according to the instantaneous condition of the input voltage and output load. The IC exhibits excellent efficiency and high PF at light load. When operating in CCM, the controller can be used in applications up to 500W with minimal board size limitations. The performance of the PFC can be optimized by programming multiple parameters through an I2C GUI. Programming is completed either by the factory or by the customer using a detailed user guide.
The half-bridge LLC converter achieves high efficiency with zero-voltage switching (ZVS). The HR1200 implements an adaptive dead-time adjustment (ADTA) function, so the LLC converter can achieve easily ZVS from heavy load to light load. In addition, the HR1200 can prevent the LLC converter from operating in capacitive mode, making it more robust and easier to design.
The HR1200 integrates a high-voltage (HV) current source inside the IC for start-up, eliminating the traditional start-up resistor or external circuit. When the AC input is removed, the HV current source functions as an X-cap discharger, eliminating the need for a resistor for