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AN1523 APPLICATION NOTE

Output voltage measurement and efficiency calculation @normal operation

In the following table the output voltage cross regulation is measured and the overall efficiency of the converter

is calculated at both the nominal input voltages. The output voltages have been measured after the load con-

nector.

The output voltages are within the tolerances in all conditions, at both full and half load. The efficiency calculated

is good for this kind of converters, then the power dissipation is low and even this affect positively the long-term

reliability of the circuit.

Output voltage measurement and efficiency calculation @stand-by operation

Like in the previous section, the output voltage and the efficiency have been checked and the input power has

been measured. It is clearly visible that with the required stand-by load (5V@50mA and 12V@0mA) the input

power consumption is well below 1W at both the input voltage range. Besides, the circuit has been characterised

at both the nominal input voltage values for different output load, giving very interesting results:

5V

12V

115Vac

Vout

@Iout

Vout

@Iout

Pin

η

[V]

[A]

[V]

[A]

[W]

[W]

full load

4.99

1.400

12.11

0.304

10.67

15.12

70.6%

half load

5.01

0.650

11.97

0.15

5.05

7.00

72.2%

5V

12V

220Vac

Vout

@Iout

Vout

@Iout

Pin

η

[V]

[A]

[V]

[A]

[W]

[W]

full load

4.99

1.400

12.11

0.304

10.67

14.90

71.6%

half load

5.01

0.650

11.99

0.15

5.05

6.90

73.3%

5V

12V

115Vac

Vout

@Iout

Vout

@Iout

Pin

η

[V]

[mA]

[V]

[mA]

[W]

[W]

5.02

10

11.92

0

0.050

0.288

17.4%

5.02

30

12.35

0

0.151

0.430

35.0%

5.02

50

12.65

0

0.251

0.579

43.3%

5.02

80

13.06

0

0.402

0.795

50.5%

5.02

100

13.27

0

0.502

0.941

53.4%