Evaluation Board Eases Design of Energy-Saving Power Supplies

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• STMicroelectronics’ eco-certified evaluation board that can deliver 400-Watt power-supply for meeting tough eco-design norms
• It incorporates support for high-efficiency burst mode and synchronous-rectification controller for achieving high average and typical efficiency across a wide load range

STMicroelectronics introduces the EVL400W-EUPL7 evaluation board that can deliver 400-Watt power-supply for meeting tough eco-design norms. The board leverages innovative features of ST’s L4984D current-mode PFC controller and L6699 resonant half-bridge controller for high energy efficiency in multiple operating modes.

High efficiency at light loads has 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:

• low quiescent current and a disable input for remote on/off control 
• power sequencing or brownout protection
• capability to switch-off the pre-regulator when operating in burst mode.

Wide load efficiency and energy-saving

The company’s SRK2001 synchronous-rectification controller (also on-board the EVL400W-EUPL7) achieves high average and typical efficiency across a wide load range. Its energy-saving ability with synchronous rectification 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.

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With a 12V output and wide AC input voltage range from 90V to 264V (45-65Hz), the EVL400W-EUPL7 provides a medium-power reference design that can meet demanding energy-saving requirements for applications such as:

• ATX supplies
• small servers and workstations
• medical equipment
• signage and LED panels.

A low no-load consumption eliminates the need for an auxiliary switched-mode power supply (SMPS) and helps save bill-of-materials (BoM) costs.

At full-load efficiency over 93 per cent at 230VAC and over 91 per cent at 110VAC with no-load mains consumption of less than 0.150W, the EVL400W-EUPL7 meets 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. It has also achieved CLEAResult®1 Plug Load Solutions® 80 PLUS™2 certification, rated Platinum at 115V AC and Gold at 230V AC. 

The EVL400W-EUPL7 is now available from authorised distributors or STMicroelectronics.