The STEVAL-LLL009V1 digitally controlled 300 W power supply consists of power factor correction (PFC) and half-bridge LCC resonant converter power stages. An STM32F334R8 microcontroller implements DC-DC and output synchronous rectification digital control, while the PFC is driven in transition mode by the L6562AT controller. The system supports constant voltage (CV) and constant current (CC) operation.
MDmesh K5 and MDmesh DK5 Power MOSFETs are used in the PFC and LCC half-bridge, respectively, to ensure maximum efficiency, while the STripFET F7 Power MOSFET is employed to reduce conduction losses in the synchronous rectification stage on the secondary side.
Both the primary and secondary sections are supplied by an off-line flyback circuit based on VIPER267KDTR high voltage converter for ultra-wide input which provides regulated voltages to the control board, the gate driver ICs and the signal conditioning circuits.
Formal testing and measurement results confirm the ability and performance of ST power products combined with comprehensive digital control to deliver high efficiency, power factor near unity, and low THD across wide input voltage and load conditions.