RT9046 Datasheet, PDF (10/11 Pages) Richtek Technology Corporation – Low-Dropout Linear Regulator Controller with PGOOD

RT9046
Layout Considerations
There are three critical layout considerations. The divider
resistors, R1 and R2, should be mounted as close to the
RT9046 FB pin as possible to minimize noise. Capacitor,
C_IN, should be as close to the MOSFET's drain as
possible, and output capacitor, C_OUT, as close to the
MOSFET's source as possible. Finally, in cases where
high load currents are required, designers will have to get
creative. MOSFETs with mountable drains, increased
copper in the layout, and fan generated air flow may be
necessary to achieve workable designs. A layout example
demonstrating passive placement and using increased
copper area for the drain of a MOSFET pass transistor in
the D-PAK package is illustrated by Figure 5.
V_IN
GND
V_CC
EN
PGOOD
FB
V_OUT
GND
Figure 5
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DS9046-01 April 2011