AN2941 Datasheet, PDF (1/37 Pages) STMicroelectronics – This application note describes the characteristics and the features

AN2941
Application note
19 V - 75 W SMPS compliant with latest ENERGY STAR^® criteria
using the L6563S and the L6566A
Introduction
This application note describes the characteristics and the features of a 75 W reference
board (p/n EVL6566A-75WES4), tailored on specifications of a typical high-end portable
computer power supply. The peculiarities of this design are the very high efficiency at light
load and the excellent global efficiency for a two-stage architecture. The high efficiency at
high load is achieved by not using synchronized rectification at the secondary side and
therefore offering a very cost-effective solution.
Efficiency during active-load and light-load operation are compliant with ENERGY STAR^®
eligibility criteria for both external (EPA rev. 2.0 EPS) and computer integrated (EPA rev. 4.0
computers) power supply. In addition this design is even compliant with the latest computer
document (EPA rev. 5.0 computers) whose effective date is July 2009.
Figure 1. L6566A and L6563S-75W ENERGY STAR^® compliant adapter
demonstration board (p/n EVL6566A-75WES4)
November 2010
Doc ID 15447 Rev 4
1/37
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