Nettop Platform for 2008 System Design White Paper

System Configuration
22 White Paper
Figure 6 Typical Input Voltage of the DC-DC Board in the Market, for example 19 V
4.3.4 Energy Star* Qualified External Power Supply (Adapter)
Tier I of the ENERGY STAR* computer specification as documented in ENERGY STAR*
Program Requirements for Computers: Version 4.0 requires that the external power
supplies for compliant computers be at least 84% average efficiency. Average
efficiency is defined as the averaging the efficiencies at 25%, 50%, 75% and 100% of
the rated output capacity. In addition, an unplugged external power supply should
consume no more than 0.75 W from the wall socket. Details can be found at
www.energystar.gov/ia/partners/product_specs/program_reqs/EPS%20Eligibility%20
Criteria.pdf.
After November 1, 2008, a new version of ENERGY STAR* Program Requirements for
Single Voltage External Ac-Dc and Ac-Ac Power Supplies specification will take effect.
Both average efficiency and no-load specification become tighter, 87% and 0.5 W
respectively. Details can be found at
www.energystar.gov/index.cfm?c=revisions.eps_spec. A system designer should
consider the version of the Energy Star* compliant power supply when designing an
Energy Star* compliant system.
Reference:
Power Supply Design Guide for Desktop Form Factors
ENERGY STAR* Program Requirements for Computers
ENERGY STAR* System Implementation white paper
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Adaptor
19V
DC-DC Board
DC Regulator
19V
12V
5V
3.3V
-12V
5VSB
System