ST Eco-Certified 400W Power Supply Evaluation board reduces the difficulty of advanced energy-saving power supply design

     STMicroelectronics' EVL400W-EUPL7 evaluation board is an off-the-shelf 400W power solution that complies with today's most demanding eco-design specifications and leverage the innovative capabilities of ST's L4984D electro-current PFC controller and L6699 resonant half-bridge controller. Maximizes power efficiency in a variety of operating modes.

     230VAC input full load energy efficiency of more than 93%, 110VAC input full load energy efficiency of more than 91%, no load power consumption of less than 0.150W, in line with ENERGYSTAR Energy STAR Version 6.1 computer power efficiency requirements, European EuP Lot 6 Tier 2 energy efficiency requirements for home appliances and office equipment. And the Code of Conduct (CoC) Version 5 Tier 2 External power supply efficiency regulations. The EVL400W-EUPL7 also received the CLEAResult 1 Plug Load Solutions 80 PLUS™2 certificate, rated as a Platinum power solution for 115V AC input voltage and a gold power solution for 230V AC input voltage.

     The board's high energy efficiency under light loads is evaluated because the L4984D and L6699 support burst mode, and the L6699's adaptive dead-time control reduces the primary side current. Both the L4984D and L6699 have a small static current, a disable input pin for remote on/off control, and can be used for power sequencing or power down protection. In burst mode, the two devices can also interact to turn off the preregulator.

     With ST's SRK2001 synchronous rectifier controller on board, the EVL400W-EUPL7 achieves high average and typical energy efficiency over a wide load range. The method of saving power through synchronous rectification can also use a small volume radiator on the secondary side. The built-in active high-voltage start circuit uses a depletion MOSFET design to reduce residual power consumption in normal operating mode to a negligible level and ensure a short start time.

     The EVL400W-EUPL7 outputs 12V voltage and inputs 90V-264V(45-65Hz) AC voltage, providing power developers with a medium power reference design to meet the most stringent energy saving goals for ATX power supplies, small servers and workstations, medical equipment, signage, LED panels and other applications. Due to its low no-load power consumption, there is no need to load auxiliary switching power supplies (SMPS), so the design also helps save bill of materials (BoM) costs.