LTM4609 LINER [Linear Technology], LTM4609 Datasheet - Page 20

• Manufacturer Part Number: LTM4609
• Description: 36VIN, 34VOUT High Effi ciency Buck-Boost DC/DC ?Module
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
LTM4609
Layout Checklist/Example
The high integration of LTM4609 makes the PCB board
layout very simple and easy. However, to optimize its electri-
cal and thermal performance, some layout considerations
are still necessary.
• Use large PCB copper areas for high current path, includ-
• Place high frequency input and output ceramic capaci-
• Route SENSE
• Place a dedicated power ground layer underneath the
• To minimize the via conduction loss and reduce module
• Do not put vias directly on pads, unless the vias are
TYPICAL APPLICATIONS
20
ing V
minimize the PCB conduction loss and thermal stress.
tors next to the V
high frequency noise
PC trace spacing. Avoid sense lines passing through
noisy areas, such as switch nodes.
unit.
thermal stress, use multiple vias for interconnection
between the top layer and other power layers
capped.
IN
, R
SENSE
–
and SENSE
, SW1, SW2, PGND and V
IN
, PGND and V
12V TO 36V
+
leads together with minimum
V
IN
1.5k
R1
R3
1k
Figure 16. Buck Mode Operation with 12V to 36V Input
OUT
10μF
50V
×2
pins to minimize
ON/OFF
0.1μF
C3
OUT
. It helps to
PGOOD
RUN
COMP
INTV
PLLFLTR
EXTV
STBYMD
SS
SGND
CC
CC
V
LTM4609
IN
PGND
PLLIN
• Use a separated SGND ground copper area for com-
Figure 15. gives a good example of the recommended
layout.
SENSE
SENSE
SW1
V
PGND
R
ponents connected to signal pins. Connect the SGND
to PGND underneath the unit.
OUT
SENSE
V
SW1
SW2
FCB
C
OUT
V
OUT
FB
+
–
CLOCK SYNC
4.7μH
L1
R
7.15k
Figure 15. Recommended PCB Layout
FB
R2
9mΩ
KELVIN CONNECTIONS TO R
4609 TA02
+ –
+
L1
R
100μF
25V
SENSE
SGND
V
12V
10A
OUT
SW2
V
IN
SENSE
R
SENSE
PGND
C
IN
4609 F15
4609fa