Evaluation board simplifies eco-design of power supplies

STMicroelectronics has simplified the design of energy-saving power supplies with the introduction of its EVL400W-EUPL7 evaluation board. The ready-to-use 400-watt (W) power-supply solution meets today’s toughest energy-efficiency and eco-design requirements, including Energy Star, European EuP, and Code of Conduct (CoC).

Leveraging ST’s L4984D current-mode PFC controller and L6699 resonant half-bridge controller to maximize energy efficiency in multiple operating modes, the board delivers full-load efficiency of over 93% at 230 VAC and over 91% at 110 VAC, with no-load mains consumption of less than 0.150 W. The board meets Energy Star Version 6.1 requirements for computers, European EuP Lot 6 Tier 2 requirements for household and office equipment, and CoC Version 5 Tier 2 for external power supplies.

The EVL400W-EUPL7 also meets CLEAResult Plug Load Solutions 80 PLUS certification, rated Platinum at 115 VAC and Gold at 230 VAC.

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, said STMicroelectronics. Both devices offer low quiescent current and a disable input that allows remote on/off control and can be used for power sequencing or brownout protection. They can also interact to switch-off the pre-regulator when operating in burst mode.

The EVL400W-EUPL7, with ST’s SRK2001 synchronous-rectification controller on-board, achieves high average and typical efficiency across a wide load range, according to the company, and allows for a small heat sink at the secondary side. The board also includes a built-in active high-voltage startup circuitry, designed with a depletion MOSFET, that reduces the residual consumption in normal operation to a negligible level and ensures a fast startup time.

The EVL400W-EUPL7 provides a medium-power reference design ready, with a 12-V output and AC input-voltage range from 90 V to 264 V (45-65 Hz) to meet energy-saving targets for applications such as ATX supplies, small servers, and workstations, medical equipment, signage, and LED panels. It also eliminates the need for an auxiliary switched-mode power supply (SMPS) with low no-load consumption. Available to order, the EVL400W-EUPL7 is priced at $180.