5/5 Rev. A /01-2010
Figure 3
(7.6) Freewheeling Diode Selection
The freewheeling diode conduction time is longer than the N-channel Power MOS off time.
Therefore, the diode parameters improve the overall efficiency. Using Schottky diodes as
freewheeling rectifiers reduces diode reverse recovery time and the voltage drop across the diode
is lower. For this design, choice RB520S-30, with 30V reverse voltage, 0.2A forward current, and
around 0.4V forward voltage drop.
The freewheeling diode should be place close to the SW pin of the AME5150 to minimize noise
coupling due to trace inductance.
