AN3286 datasheet(20/42 Pages) STMICROELECTRONICS

20 / 42 page

Testing the board

AN3286

20/42

Doc ID 17998 Rev 1

Figure 21.

Input voltage averaged efficiency vs. load

In version 2.0 of the ENERGY STAR program requirements for single voltage external AC-

DC and AC-AC power supplies (1.), the power supplies are divided into two categories: low

voltage power supplies and standard power supplies, with respect to the nameplate output

voltage and current. To be considered a low-voltage power supply, an external power supply

must have a nameplate output voltage of less than 6 V and a nameplate output current of

more than or equal to 550 mA.

The following tables report the EPA energy efficiency criteria for AC-DC power supplies in

active mode for standard models and low voltage models respectively.

Table 11.

Energy efficiency criteria for standard models

Nameplate output power (Pno)

Minimum average efficiency in active mode

(expressed as a decimal)

0 to

≤ 1 watt

≥ 0.48*Pno+0.140

> 1 to

≤ 49 watts

≥ [0.0626 * In (Pno)] + 0.622

> 49 watts

≥ 0.870

Table 12.

Energy efficiency criteria for low voltage models

Nameplate output power (Pno)

Minimum average efficiency in active mode

(expressed as a decimal)

0 to

≤ 1 watt

≥ 0.497 *Pno+0.067

> 1 to

≤ 49 watts

≥ [0.075 * In (Pno)] + 0.561

> 49 watts

≥ 0.860

AN3286 Datasheet(PDF) 20 Page - STMicroelectronics