Diodes AP65402 - Manual (Page 12)

AP65402
Document number: DS37107 Rev. 1 - 2
12 of 15
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April 2014
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AP65402
Application Information
(cont.)
PC Board Layout
This is a high switching frequency converter. Hence attention must be paid to the switching currents interference in the layout. Switching current
from one power device to another can generate voltage transients across the impedances of the interconnecting bond wires and circuit traces.
These interconnecting impedances should be minimized by using wide, short printed circuit traces. Note that the IN to GND decoupling
capacitors need to be immediately adjacent to the IN and GND pins of the device (U1), and 12 thermal vias from the back side thermal pad to
the GND plane are essential to achieve the best operation at full load current.
Figure 4. PC Board Layout
External Bootstrap Diode
It is recommended that an external bootstrap diode be added when the input voltage is no greater than 5V or the 5V rail is available in the
system. This helps to improve the efficiency of the regulator. This solution is also applicable for D > 65%. The bootstrap diode can be a low cost
one such as BAT54 or a Schottky that has a low V
F
.
Figure 5—External Bootstrap Compensation Components
Recommended Diodes:
Part Number
Voltage/Current
Rating
Vendor
B130 30V, 1A Diodes Inc
SK13 30V, 1A Diodes Inc