AN1673 APPLICATION NOTE

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The PFC section of the present application has been designed to pre regulate 400V and to deliver 80W.

The AC mains voltage can range from 85V to 264 V.

For a detailed description of the L6561 operation, refer to AN966.

Evaluation result.

The demo board has been evaluated in two different modes. The first evaluation (see table_01) has been

done for the resonant converter section (not included the PFC pre regulator circuit) at two different output

power levels.

In practice the resonant converter has been supplied using a 400V DC power supply and it has been eval-

uated its efficiency.

Table 1.

Input supply Voltage = +400 VDC

The second evaluation (see Table 2) has been done for the entire application circuit, including the PFC.

The load has been changed as in the first evaluation (3.8A and 2A), moreover it have been set four sig-

nificant values of the mains voltage according to the requested wide range.

Table 2a.

Output loaded @ 3.8A.

Table 2b.

Half load (@ 2A).

Pin=72W

Vo=17.8V

Io=3.8A

Po=67.64

n=93.9%

Pin=39W

Vo=17.8V

Io=2A

Po=35.6

n=91.3%

Vin=88Vac

Pin=77.5W

Vo=17.8V

Io=3.8A

Po=67.64

n=87.3%

Vin=110Vac

Pin=76.35W

Vo=17.8V

Io=3.8A

Po=67.64

n=88.6%

Vin=220Vac

Pin=74.7W

Vo=17.8V

Io=3.8A

Po=67.64

n=90.5%

Vin=255 Vac

Pin=74.4W

Vo=17.8V

Io=3.8A

Po=67.64

n=91%

Vin=88Vac

Pin=41W

Vo=17.82V

Io=2A

Po=35.64

n=86.93%

Vin=110Vac

Pin=40.5W

Vo=17.82V

Io=2A

Po=35.64

n=88%

Vin=220Vac

Pin=40.3W

Vo=17.82V

Io=2A

Po=35.64

n=88.4%

Vin=255 Vac

Pin=40.3W

Vo=17.82V

Io=2A

Po=35.64

n=88.4%