LTM4605
19
4605fd
For more information www.linear.com/LTM4605
applications inForMation
Layout Checklist/Example
The high integration of LTM4605 makes the PCB board
layout very simple and easy. However, to optimize its
electrical and thermal performance, some layout consid
-
erations are still necessary.
• Use large
PCB copper areas for high current path, includ-
ing V
IN
, R
SENSE
, SW1, SW2, PGND and V
OUT
. It helps to
minimize the PCB conduction loss and thermal stress.
• Place high frequency input and output ceramic capaci
-
tors next to the V
IN
, PGND and V
OUT
pins to minimize
high frequency noise
• Route SENSE
–
and SENSE
+
leads together with minimum
PC trace spacing. Avoid sense lines passing through
noisy areas, such as switch nodes.
• Place a dedicated power ground layer underneath the
unit.
• To minimize the via conduction loss and reduce module
thermal stress, use multiple vias for interconnection
between the top layer and other power layers
• Do not put vias directly on pads, unless the vias are
capped.
• Use a separated SGND ground copper area for com
-
ponents connected to signal pins. Connect the SGND
to PGND underneath the unit.
Figure 13. gives a good example of the recommended
layout.
Figure 13. Recommended PCB Layout
V
OUT
C
OUT
V
IN
R
SENSE
R
SENSE
PGND
SW1
L1
SW2
PGND
SGND
+
C
IN
4605 F13
KELVIN CONNECTIONS TO R
SENSE
–
