Testing the board

AN4116

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Doc ID 023220 Rev 1

disproportionally better than requirements, it is worth noting that often AC-DC adapter or

battery charger manufacturers have very strict requirements about no load consumption and

if the converter is used as an auxiliary power supply, the line filter is often the big line filter of

the entire power supply that increases greatly the standby consumption.

Even though version 4 of the Code of Conduct does not have other requirements regarding

light load performance, in order to give a more complete overview, we report the input power

and efficiency of the demonstration board also in two other low load cases.

Table 8 and 14

show the performance when the output load is 25 mW and 50 mW respectively.

The input power vs. input voltage for no and light load conditions (

Table 7, 8 and 14) are

reported in the diagrams below.

Table 8.

Efficiency (%)

IC externally

biased

IC self-biased

IC externally

biased

IC self-biased

90

25

49.7

128

50.30

19.6

115

25

51.5

157

48.54

15.9

150

25

54.7

200

45.70

12.5

180

25

57.3

236

43.63

10.6

230

25

61.7

296

40.52

8.4

265

25

64.8

337

38.58

7.4

Table 9.

PIN [mW]

Efficiency (%)

IC externally

biased

IC self-biased

IC externally

biased

IC self-biased

90

50

82.4

167

60.71

29.94

115

50

85.0

198

58.82

25.25

150

50

89.3

242

55.99

20.66

180

50

93.0

280

53.76

17.86

230

50

98.0

341

51.02

14.66

265

50

101.1

384

49.46

13.02