With a new set of requirements by the United States Department of Energy (DOE) that took effect in February 2016, US regulators further reduced the amount of energy that may be consumed by external power adapters for charging smart phone, tablet and notebook PC. The latest DoE VI specification incorporates new requirements, one for average active mode efficiency and one for no load power consumption for external adapters.

These requirements drive the need for new solutions that may cost more in the end product but will save the consumer money when taking into consideration reduced greenhouse gases and energy usage.

The European Union also published its Code of Conduct (CoC) on Energy Efficiency of External Power Supplies Version 5 in late 2013. Tier 1 effectively harmonizes the EU with DoE Level VI. The more stringent Tier 2 became effective on a voluntary basis from January 2016 and on a mandatory basis in 2018.

Energy Standard Specification

Year Introduced

Year Mandatory

US DoE level VI



EU CoC Tier 1 ver. 5



EU CoC Tier 2 (More stringent)