Test board: design and evaluation

AN4007

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Doc ID 022455 Rev 2

Figure 4.

Line and load regulation

1.2

Efficiency and light load measurements

Any external power supply (EPS) must be capable to meet the international regulation

agency limits. The european code of conduct (EC CoC) and US department of energy (DoE-

US EISA 2007) limits are taken as reference. EPS limits are fixed up to 76.4%, when the

average efficiency is measured. The average efficiency measures the average value at

25%, 50%, 75% and 100% of the rated output power, at both 115 Vac and 230 Vac.

Table 4

and

Table 5 show the results:

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.95

5.00

5.05

5.10

5.15

115Vac

230Vac

Output current [mA]

AM11343v1

Table 4.

Load

Efficiency

25%

0.754.973.734.76

78.31%

50%

1.5

4.97

7.46

9.65

77.25%

75%

2.25

4.97

11.17

14.75

75.74%

100%

3

4.97

14.91

19.86

75.08%

Average efficiency

76.59%