

SIMPLICITY MEETS PERFORMANCE
ON A BUDGET
Boost efficiency with 1kW analog bridgeless PFC (BARBI topology) from ST & WE
The EVL4986A-1KWBL demonstration board is a bridgeless PFC pre-regulator, double boost topology, featuring 1 kW output power (400 Vdc) and a wide input voltage range (90 Vac-265 Vac) based on the new L4986A peak current mode CCM power factor controller. It is intended as a front-end converter up to 1 kW, able to comply with IEC61000-3-2 and JEITA-MITI.
The demo is designed on the double boost (Barbi) topology using two branches, each consisting of a boost stage, managing half the main cycle. Each section operates at an almost fixed frequency (65 kHz).
Thanks to the bridgeless approach and the L4986A control IC, the board offers high efficiency and low input current THD across the entire input voltage range.
This is achieved using a low-complexity schematic and fewer components compared to similar bridgeless solutions. The EMI standards are met in accordance with EN55022 Class-B thanks to the Würth Elektronik filter components.
EVL4986-1KWBL demonstration board

Figure: EVL4986-BL1KW 1.0 kW bridgeless PFC (BARBI) board schematic
Key features:
- • Input mains range: 90 to 265 Vac - frequency 45 to 65 Hz
- • Output voltage / load: 400 V / 2.5 A
- • Efficiency:
above 98% at 230 Vac (full load)
above 95.5% at 115 Vac (full load)
above 94% between 10% and 100% of full load
- • No load mains consumption: below 250 mW at 230 Vac
- • Mains harmonics in compliance with EN61000-3-2 Class-A and JEITA-MITI, Class-A
- • EMI in accordance with EN55022 Class-B
- • Safety in accordance with EN62368
- • Dimensions 145 x 160 mm, height = 35 mm
- • PCB: double sided, 70 µm, FR-4, mixed PTH/SMT
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