Wide range of VDD voltage

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design to achieve various behaviors. In Figure 3 on page 7 a forward configuration has been

chosen to supply the device with two benefits:

■

As soon as the device starts switching, it immediately receives some energy from the

auxiliary winding. C5 can be therefore reduced and a small ceramic chip (100nF) is

sufficient to insure the filtering function. The total start up time from the switch on of input

voltage to output voltage presence is dramatically decreased.

■

The output current characteristic can be maintained even with very low or zero output

voltage. Since the TSM101 is also supplied in forward mode, it keeps the current

the input voltage, that is to say with a ratio of about 4 for a wide range application.