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AN1621 APPLICATION NOTE

Figure 7. Efficiency versus Output Load Current at min.,typ. and max. AC Voltage.

The efficiency is quite constant and equal or above 85% from 2A to full load.

At min. load of 0.5A, it's 70% at 220Vac. The total losses, for an amount of 3.6W are mainly due to Coss of the

power mos devices and transformer core losses due to the magnetizing current.

Fig 8. shows the load transient response, at nominal ac input voltage value and output load variation from 1A

to 12A, in a couple of msec, and fig 9 shows the enlarged section at the moment of current load rise.

Fig 10. To be noticed the absence of output overshoot on the output voltage.

Figure 8. Output Voltage Response to Load Transient

0

2

4

6

8

10

12

14

65

70

75

80

85

90

η

(%)

D96IN463

176Vac

220Vac

265Vac

D96IN464

CH1: Vo (100mV/div)

CH2: Io (5A/div)

T: 1ms/div