Datasheet

LTM4613
20
4613f
Safety Considerations
The LTM4613 modules do not provide isolation from V
IN
to V
OUT
. There is no internal fuse. If required, a slow blow
fuse with a rating twice the maximum input current needs
to be provided to protect each unit from catastrophic
failure.
Layout Checklist/Example
The high integration of LTM4613 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, in-
cluding V
IN
, PGND and V
OUT
. It helps to minimize the
PCB conduction loss and thermal stress.
• Place high frequency ceramic input and output capaci-
tors next to the V
D
, PGND and V
OUT
pins to minimize
high frequency noise.
• Place a dedicated power ground layer underneath the
unit.
• Use round corners for the PCB copper layer to minimize
the radiated noise.
• To minimize the EMI noise and reduce module thermal
stress, use multiple vias for interconnection between
top layer and other power layers.
• Do not put vias directly on pads.
• If vias are placed onto the pads, the the vias must be
capped.
• Interstitial via placement can also be used if necessary.
• Use a separated SGND ground copper area for com-
ponents connected to signal pins. Connect the SGND
to PGND underneath the unit.
• Place one or more high frequency ceramic capacitors
close to the connection into the system board.
Figure 17 gives a good example of the recommended layout.
APPLICATIONS INFORMATION
Table 4. 5V Output
DERATING CURVE V
IN
(V) POWER LOSS CURVE AIRFLOW (LFM) HEAT SINK
θ
JA
(°C/W)
Figure 11 36 Figure 10 0 None ≈11
Figure 11 36 Figure 10 200 None ≈9
Figure 11 36 Figure 10 400 None ≈9
Figure 12 36 Figure 10 0 BGA Heat Sink ≈11
Figure 12 36 Figure 10 200 BGA Heat Sink ≈8.5
Figure 12 36 Figure 10 400 BGA Heat Sink ≈8.5
Heat Sink Manufacturer
Wakefield Engineering Part No: LTN20069 Phone: [phone]
Table 3. 12V and 15V Outputs
DERATING CURVE V
IN
(V) POWER LOSS CURVE AIRFLOW (LFM) HEAT SINK
θ
JA
(°C/W)
Figures 13, 15 24, 36 Figure 9 0 None ≈14
Figures 13, 15 24, 36 Figure 9 200 None ≈10
Figures 13, 15 24, 36 Figure 9 400 None ≈10
Figures 14, 16 24, 36 Figure 9 0 BGA Heat Sink ≈13
Figures 14, 16 24, 36 Figure 9 200 BGA Heat Sink ≈8
Figures 14, 16 24, 36 Figure 9 400 BGA Heat Sink ≈8