Board testing

AN4345

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DocID025078 Rev 1

In this manner, the board is compliant with the above mentioned standards, see Figure 18,

are plotted with dotted lines. In the same figure the efficiency at 25%, 50%, 75% and 100%

of load for both input voltages is also shown.

Figure 18. Active mode efficiency and comparison with CoC5 and DOE standards

CoC5 standard has also some requirements on the active mode efficiency when the output

load is 10% of the nominal output power. The comparison between the requirement for an

external power supply with a power throughput of 1.5 W and the performance of the

evaluation board is shown in Table 5, where the STEVAL-ISA119V1 is Tier 1 and Tier 2

compliant.

4.5

Light load performance

In the version 5 of the Code of Conduct, the power consumption of the power supply is

considered even if it is not loaded. Concerning standards, Table 6 gives some indications:

In no load condition and with different input voltages, the input power of the converter has

been measured and results are reported in Table 7.

Table 5. CoC5 requirement and performance at 10% output load

CoC5 minimum efficiency requirement in active mode at 10% of full

Board

performance

Tier 1

Tier 2

57.4%

60%

62.7%

AM13823V1

60

62

64

66

68

70

72

74

76

78

80

0.2

0.4

0.6

0.8

1

115

230

av @ 115Vac

av @ 230Vac

DOE

CoC 5Tier 2

CoC 5Tier 1

Table 6. Energy consumption criteria for no load

Nameplate output power (Pno)

Maximum power in no load for AC-DC EPS

Tier 1

Tier 2

0.3 W < Pno

≤ 49 W

0.15 W

0.075 W

50 W < Pno < 250 W

0.25 W

0.15 W