The UCC29950D is a continuous conduction-mode Power Factor Correction (PFC) and LLC Combo Controller provides all the control functionality for an AC to DC converter with a CCM boost power factor correction (PFC) stage followed by an LLC converter stage. The controller is optimized to allow ease of use. Proprietary CCM PFC algorithms enable the system to achieve high efficiency, smaller converter size with high power factor. The integrated LLC controller enables a high-efficiency DC to DC conversion stage utilizing soft switching for low EMI noise. Integration of PFC control and LLC control in a combo controller allows the control algorithms to take advantage of information from both stages. The controller includes a control circuit for start-up using a Depletion Mode MOSFET with internal device power management that minimizes external component requirements and helps lower system implementation costs. To further reduce the standby power an X-Cap discharge circuit is integrated.
High efficiency PFC and half-bridge resonant LLC combo controller
Continuous conduction mode (CCM) boost power factor correction
Supports self-bias or auxiliary (external) bias mode of operation
PFC loops fully internally compensated
PFC stage design in 3 easy steps
True input power limit, independent of line voltage
Dead-time varied across load range for LLC half-bridge power stage to extend ZVS range
Three-level LLC over-current protection
Hiccup mode operation for continuous overload and short-circuit power protection
Low standby power consumption enabled by active control of high-voltage start-up MOSFET
Built in soft-start and converter sequencing to simplify design
AC Line brownout protection, with fail indicator
PFC bus over-voltage and under-voltage protection
Over-temperature protection
External gate drivers for scalability with power level