AN4077

Test results and significant waveforms

Doc ID 022997 Rev 1

11/33

The power factor (PF) and the total harmonic distortion (THD) have been measured too and

the results are reported in

Figure 7 and Figure 8. As can be seen, the PF remains close to

unity throughout the input voltage mains and the total harmonic distortion is very low.

The measured efficiency is shown in

Figure 9, measured according to the ES-2

requirements: it is very good at all load and line conditions. At full load it is always higher

than 94%, making this design suitable for high efficiency power supply. The average

efficiency calculated according to the ES-2 requirements at different nominal mains voltage

are reported in the diagram of

Figure 10.

Figure 5.

L6564H 100 W TM PFC

demonstration board: input current

waveform at 230 V-50 Hz-100 W load

Figure 6.

L6564H 100 W TM PFC

demonstration board: input current

waveform at 100 V-50 Hz-100 W load

Figure 7.

L6564H 100 W TM PFC

demonstration board: power factor

vs output power

Figure 8.

L6564H 100 W TM PFC

demonstration board: THD vs

output power

0.75

0.78

0.81

0.84

0.87

0.9

0.93

0.96

0.99

Pout =100W

Pout =75W

Pout =50W

Pout =25W

Output Power

PF @100Vac-50Hz

PF @115Vac-60Hz

PF @230Vac-50Hz

AM11532v1

AM11533v1

1.00%

1.50%

2.00%

2.50%

3.00%

3.50%

4.00%

4.50%

5.00%

5.50%

6.00%

Pout =100W

Pout =75W

Pout =50W

Pout =25W

Output Power

THD @100Vac-50Hz

THD @115Vac-60Hz

THD @230Vac-50Hz