EVL400W-EUPL7: 400W, 12V @ 33A, 90 ~ 264VAC

The EVL400W-EUPL7 demonstration board with an output of 12V at 33A, 400W AC/DC converter, tailored for the typical specification of an AC/DC adapter with wide input mains range, very low power consumption at light load and good average efficiency. The architecture is based on a two-stage approach: a front-end PFC pre-regulator based on a CCM (continuous conduction mode) boost PFC controller using the L4984, and a downstream LLC resonant half-bridge converter, designed around the L6699.

At the secondary side, synchronous rectification is implemented by means of the SRK2001 that assures a very high rectification efficiency with consequent small Heat Sink required.

The PFC section uses a proprietary LM-FOT (line-modulated fixed-off-time) that allows control methodology at fixed frequency operation for boost PFC converters as long as its operating in CCM.

The LLC section uses the L6699, a double-ended controller specific to series-resonant half-bridge topology. The output voltage regulation is obtained by modulating the operating frequency.

The main focus of this demonstration board is the light-load efficiency, achieved through the burst mode function of both PFC and LLC controllers with the self-adaptive deadtime of the L6699, modulated by the internal logic according to the half-bridge node transition times, which allows the maximization of the transformer magnetizing inductance, reducing the primary current at light load operation.

An active high voltage start-up circuitry based on a depletion MOSFET provides a very fast start-up time and minimizes the residual consumption during normal operation to a negligible level.

• Universal input mains voltage range: from 90 Vac to 264 Vac frequency from 45 to 65 Hz

• Overall efficiency at full load: >89%, according to ENERGY STAR® 6.1 limit for computers

• Certified as 80Plus PLATINUM level at 115 Vac and GOLD level at 230 Vac in the CLEAResult Plug Load Solutions website

• Average efficiency: >89%, according to European CoC ver. 5 Tier 2 for external power supplies

• Efficiency at 250mW >50%, well above EuP lot 6 Tier 2 limit for household and office equipment

• No load mains consumption: <150mW at 230 Vac, well below European CoC ver. 5 Tier 2 limit for external power supplies

• Mains harmonics: meets EN61000-3-2 Class-D and JEITA-MITI Class-D

• EMI: according to EN55022 Class-B

• Safety: meets EN60950 standards