The board leverages innovative features of ST’s L4984D current-mode PFC controller and L6699 resonant half-bridge controller to maximize energy efficiency in multiple operating modes.
The full-load efficiency is over 93% at 230VAC and over 91% at 110VAC — with no-load mains consumption of less than 0.150W. This meets the ENERGY STAR Version 6.1 requirements for computers, European EuP Lot 6 Tier 2 requirements for household and office equipment, and CoC (Code of Conduct) Version 5 Tier 2 for external power supplies.
The EVL400W-EUPL7 has also achieved CLEAResult1 Plug Load Solutions 80 PLUS2 certification, rated Platinum at 115V AC and Gold at 230V AC.
An extremely high-efficiency at light loads leverages support for burst mode, featured in the L4984D and L6699, as well as the L6699’s self-adaptive dead-time that allows for reduced primary current. The L4984D and L6699 each have a low-quiescent current and a disable input that allows remote on/off control and can be used for power sequencing or brownout protection.
The two devices can also interact to switch-off the pre-regulator when operating in burst mode.
With ST’s SRK2001 synchronous-rectification controller also on-board, the EVL400W-EUPL7 achieves high average and typical efficiency across a wide load range. Saving energy with synchronous rectification also allows a small heatsink at the secondary side.
Built-in active high-voltage startup circuitry, designed with a depletion MOSFET, reduces the residual consumption in normal operation to a negligible level and ensures a fast startup time.
Having a 12V output and wide AC input-voltage range from 90V to 264V (45-65Hz), the EVL400W-EUPL7 provides a medium-power reference design ready to meet the most aggressive energy-saving targets for applications such as ATX supplies, small servers and workstations, medical equipment, signage, and LED panels.
With its low no-load consumption, which eliminates the need for an auxiliary switched-mode power supply (SMPS), the design also helps save bill-of-materials (BoM) costs.