AN1673 Datasheet, PDF (22/24 Pages) STMicroelectronics – L6598 OFF-LINE CONTROLLER FOR RESONANT CONVERTERS

AN1673 APPLICATION NOTE
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
Pin=72W
Vo=17.8V
Pin=39W
Vo=17.8V
Io=3.8A
Io=2A
Po=67.64
Po=35.6
n=93.9%
n=91.3%
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.
Vin=88Vac
Pin=77.5W
Vin=110Vac
Pin=76.35W
Vin=220Vac
Pin=74.7W
Vin=255 Vac
Pin=74.4W
Vo=17.8V
Vo=17.8V
Vo=17.8V
Vo=17.8V
Io=3.8A
Io=3.8A
Io=3.8A
Io=3.8A
Po=67.64
Po=67.64
Po=67.64
Po=67.64
n=87.3%
n=88.6%
n=90.5%
n=91%
Table 2b.
Half load (@ 2A).
Vin=88Vac
Pin=41W
Vin=110Vac
Pin=40.5W
Vin=220Vac
Pin=40.3W
Vin=255 Vac
Pin=40.3W
Vo=17.82V
Vo=17.82V
Vo=17.82V
Vo=17.82V
Io=2A
Io=2A
Io=2A
Io=2A
Po=35.64
Po=35.64
Po=35.64
Po=35.64
n=86.93%
n=88%
n=88.4%
n=88.4%
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