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


Manufacturer STMicroelectronics
Category AC/DC and DC/DC Conversion
Sub-Category AC/DC SMPS - Single Output
Eval Board Part Number 497-EVL400W-EUPL7-ND
Eval Board Supplier STMicroelectronics
Eval Board Normally In Stock
AC Voltage Universal (115 / 230V)
Outputs and Type 1 Isolated
Voltage Out 12 V
Current Out 33 A
Output Power 400 W
Features Light Load Mode
Over Current Protection
Reset Function
Short Circuit Protection
Soft Start
Efficiency @ Conditions >92%, 230 VAC in, 12V @ 80 ~ 400 W
>90%, 115 VAC in @ 60 ~ 380 W
No-load Input Power @ Voltage <125 mW @ 115 VAC
<140 mW @ 230 VAC
Switching Frequency 200 kHz
Internal Switch No
Component Count + Extras 203 + 41
Voltage In 88 ~ 264 VAC
Design Author STMicroelectronics
Application / Target Market Distributed Power Systems
Industrial Power
Main I.C. Base Part L4984D
Date Created By Author 2019-11
Date Added To Library 2020-08

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