AN2950 datasheet(18/37 Pages) STMICROELECTRONICS

18 / 37 page

Testing the board

AN2950

18/37

Doc ID 15494 Rev 1

Figure 23.

ENERGY STAR

efficiency criteria

The presented power supply belongs to the low-voltage power supply category and, in order

to be compliant with ENERGY STAR

requirements, needs to have an efficiency higher

than 73.37%. For all the considered input voltages, the efficiency (see Table 8) results are

higher than the recommended value.

2.5

Light load performances

The input power of the converter has been measured in no load conditions for different input

voltages. The results are reported in Table 13.

Version 2.0 of the ENERGY STAR® program also takes into consideration the power

consumption of the power supply when it is not loaded. The criteria to be compliant with are

reported in Table 14.

The performance of the presented board is much better than the requirement; the power

consumption is about twelve times lower than the ENERGY STAR

limit.

Table 13.

No load input power

VIN_AC (VRMS)

Pin (mW)

13.8

115

14.5

150

180

230

265

Table 14.

Energy consumption criteria for no load

Nameplate output power (Pno)

Maximum power in no load for AC-DC EPS

0 to = 50 W

< 0.3 W

> 50 W < 250 W

< 0.5 W

AN2950 Datasheet(PDF) 18 Page - STMicroelectronics