ltm4628 Linear Technology Corporation, ltm4628 Datasheet - Page 29

• Manufacturer Part Number: ltm4628
• Description: Ltm4628 - Dual 8a Or Single 16a Dc/dc ?module Regulator
• Manufacturer: Linear Technology Corporation

APPLICATIONS INFORMATION
Safety Considerations
The LTM4628 modules do not provide galvanic isolation
from V
a slow blow fuse with a rating twice the maximum input
current needs to be provided to protect each unit from
catastrophic failure. The device does support thermal
shutdown and over current protection. A temperature diode
is provided for monitoring internal temperature.
Layout Checklist/Example
The high integration of LTM4628 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 paths,
• Place high frequency ceramic input and output capaci-
including V
mize the PCB conduction loss and thermal stress.
tors next to the V
high frequency noise.
IN
to V
OUT
IN
, GND, V
. There is no internal fuse. If required,
IN
, PGND and V
OUT1
and V
GND
C
V
OUT1
OUT1
M
K
H
G
D
C
B
A
OUT2
L
J
F
E
C
OUT
IN1
1
. It helps to mini-
pins to minimize
2
Figure 27. Recommended PCB Layout
3
CNTRL
4
5
6
GND
V
IN
7
• Place a dedicated power ground layer underneath the
• To minimize the via conduction loss and reduce module
• Do not put via directly on the pad, unless they are
• Use a separated SGND ground copper area for com-
• For parallel modules, tie the V
• Bring out test points on the signal pins for monitoring.
Figure 27 gives a good example of the recommended
layout.
CNTRL
8
unit.
thermal stress, use multiple vias for interconnection
between top layer and other power layers.
capped or plated over.
ponents connected to signal pins. Connect the SGND
to GND underneath the unit.
together. Use an internal layer to closely connect these
pins together. The TRACK pin can be tied a common
capacitor for regulator soft-start.
9
10
11
12
C
IN2
V
OUT2
C
GND
OUT2
4628 F27
SGND
OUT
, V
FB
LTM4628
, and COMP pins
29
4628f