Datasheet
LTM4602HV
16
4602hvf
Figure 17. 12V to 3.3V (950kHz),
BGA Heatsink
Figure 19. 24V to 3.3V, BGA Heatsink
Figure 18. 24V to 3.3V, No Heatsink
APPLICATIO S I FOR ATIO
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Layout Checklist/Example
The high integration of the LTM4602HV makes the PCB
board layout very simple and easy. However, to optimize
its electrical and thermal performance, some layout con-
siderations 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
IN
, PGND and V
OUT
pins to minimize
high frequency noise
• 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 top layer and other power layers
Table 4. 3.3V Output
AIR FLOW (LFM) HEATSINK θ
JA
(°C/W)
0 None 15.2
200 None 14.6
400 None 13.4
0 BGA Heatsink 13.9
200 BGA Heatsink 11.1
400 BGA Heatsink 10.5
Table 3. 1.5V Output
AIR FLOW (LFM) HEATSINK θ
JA
(°C/W)
0 None 15.2
200 None 14
400 None 12
0 BGA Heatsink 13.9
200 BGA Heatsink 11.3
400 BGA Heatsink 10.25
TEMPERATURE (°C)
50
5
6
7
90
4602HV F16
4
3
60 70 80 100
2
1
0
CURRENT (A)
0LFM
200LFM
400LFM
TEMPERATURE (°C)
50
5
6
7
90
4602HV F18
4
3
60 70 80 100
2
1
0
CURRENT (A)
0LFM
200LFM
400LFM
TEMPERATURE (°C)
50
5
6
7
90
4602HV F19
4
3
60 70 80 100
2
1
0
CURRENT (A)
0LFM
200LFM
400LFM
• Do not put via directly on pad
• Use a separated SGND ground copper area for com-
ponents connected to signal pins. Connect the SGND
to PGND underneath the unit
Figure 20 gives a good example of the recommended
layout.
LTM4602 Frequency Adjustment
The LTM4602HV is designed to typically operate at 850kHz
across most input and output conditions. The control ar-
chitecture is constant on time valley mode current control.
The f
ADJ
pin is typically left open or decoupled with an
optional 1000pF capacitor. The switching frequency has
been optimized to maintain constant output ripple over the
operating conditions. The equations for setting the operat-
ing frequency are set around a programmable constant
on time. This on time is developed by a programmable