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New Developments for External Power Supply Specs

Here’s an update on some recent activity in energy efficiency programs for external power supplies (EPSs) and a chart summarizing the specs.

Last month, the European Commission’s Ecodesign Directive tightened its Lot 7 EPS standard from the initial Tier 1 efficiency levels to Tier 2. Notable changes include the reduction of no-load power consumption for EPSs < 50 W, from 0.5 W to 0.3 W, with active mode requirements tightening up for all power level ranges.

Speaking of no-load, the newly revised Chinese Mobile Phone Standard (YD/T 1591-2009) has also toughened up its no-load requirement for USB power level EPSs to ≤ 0.15 W.

And finally, the U.S. Department of Energy (DoE) is on the verge of releasing its proposed final draft of the expansion of its EPS efficiency standard (part of EISA 2007). I wrote about its early development in a previous blog (see: When One Door Closes, Another One Opens). When finalized and published, the DoE’s mandatory standard will be the first to cover multi-output and higher power (> 250 W) EPSs. It’s also expected that the current EISA2007 EPS efficiency levels for single output power supplies <250 W will harmonize with the Ecodesign Tier 2.

The following table summarizes the requirements of the Chinese Mobile Phone, the EC Ecodesign, and the proposed EISA 2007 standards.

  EC Ecodesign Version 2 (2011)China (YD/T 1591-20091) EISA 2007 (DoE)
  Standard Voltage PS2 Low Voltage PS2  
Nameplate OutputPower (Pno) Minimum Average
Efficiency, Active Mode
Minimum Average
Efficiency, Active Mode
Minimum Average
Efficiency, Active Mode
≤ 1 watt ≥ 0.480 * Pno + 0.140 ≥ 0.497 * Pno + 0.067 0.5* Pno
> 1 to ≤ 49 watts ≥ [0.0626 * Ln (Pno)] + 0.622 ≥ [0.0750 * Ln (Pno)]
+ 0.561
 
> 1 to ≤ 51 watts ≥ [0.0626 * Ln (Pno)] + 0.622(Ecodesign only)   ≥ [0.09 * Ln (Pno)] + 0.5
> 49 watts ≥ 0.870 ≥ 0.860  
> 51 watts ≥ 0.870(Ecodesign only)   ≥ 0.850
  No-Load Power3,4,5 No-Load Power4,5 No-Load Power
< 50 watts 0.3 watts / 0.15 watts 0.3 watts / 0.15 watts 0.5 watts
≥ 50 to ≤ 250 watts 0.5 watts 0.5 watts 0.5 watts

Notes:
1. YD/T standard covers only EPS with USB output of 5 V, 500 mA to 1500 MA
2. Standard voltage power supply excludes low-voltage power supplies which are defined as < 6 volts and ≥ 550 mA
3. AC-AC is ≤ 0.5 W for all power levels
4. The YD/T no-load spec for mobile handheld battery-powered apps = < 0.15 W
5. For Ecodesign, power levels are ≤ 51 watts and > 51 watts

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