3

Rev. A, June 2001

©2001 Fairchild Semiconductor Corporation

Figure 2. Typical waveforms for the flyback regulator.

Single Transistor Forward Converters

The forward converter achieves much better transformer utilization than the flyback design

since in theory, the transformer stores no energy. There is an extra inductor in the output

power path and an additional diode as well. Single transistor forward converters are useful in

48V system designs, up to 150 watts or so. A similar problem exists in the forward converter as

in the flyback design because the drain voltage is inherently unconstrained. Leakage

nductance in the power transformer will produce large voltage spikes that must be snubbed or

clamped.

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VSAT

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PWM'ED EDGE