LM5027A Datasheet, PDF (15/28 Pages) National Semiconductor (TI) – Evaluation Board evaluation board is designed to provide

FIGURE 13. Isolated Synchronous MOSFET Drive Using a Transformer
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Evaluation Board Results
Figure 14 shows the output of the Evaluation Board starting
with a pre-bias voltage of 2.7 V. Under these conditions the
output voltage starts at 2.7 V and then increases monotoni-
cally to 3.3 V. The current into the Evaluation board (sinking)
is less than 50 mA. When the output voltage rise above the
pre-bias voltage there is approximately 400 mA of current out
of (sourced) the Evaluation Board to charge the external 220
µF capacitor. After the external capacitor is charge to 3.3 V
the current out of the power supply drop to approximately 50
mA.
FIGURE 14. Pre-Bias StartUp
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