LTM4602 LINER [Linear Technology], LTM4602 Datasheet - Page 14

• Manufacturer Part Number: LTM4602
• Description: 6A High Effi ciency DC/DC ?Module
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
LTM4602
tion loss is minimized and light load effi ciency is improved.
The penalty is that the controller may skip cycle and the
output voltage ripple increases at light load.
Paralleling Operation with Load Sharing
Two or more LTM4602 modules can be paralleled to provide
higher than 6A output current. Figure 7 shows the neces-
sary interconnection between two paralleled modules. The
OPTI-LOOP
sharing among modules to balance the thermal stress.
The new feedback equation for two or more LTM4602s
in parallel is:
where N is the number of LTM4602s in parallel.
Thermal Considerations and Output Current Derating
The power loss curves in Figures 8 and 13 can be used
in coordination with the load current derating curves
in Figures 9 to 12, and Figures 14 to 15 for calculating
an approximate θ
14
V
OUT
= 0.6V •
®
current mode control ensures good current
100k
JA
N
R
for the module with various heat
SET
+ R
SET
Figure 7. Parallel Two μModules with Load Sharing
V
IN
V
PGND
PGOOD
V
PGND
IN
IN
COMP V
COMP V
LTM4602
LTM4602
V
PGOOD
PULLUP
100k
OSET
OSET
sinking methods. Thermal models are derived from
several temperature measurements at the bench,
and thermal modeling analysis. Application Note 103
provides a detailed explanation of the analysis for the
thermal models, and the derating curves. Tables 3
and 4 provide a summary of the equivalent θ
noted conditions. These equivalent θ
correlated to the measured values, and improve with
air-fl ow. The case temperature is maintained at 100°C
or below for the derating curves. This allows for 4W
maximum power dissipation in the total module with
top and bottom heat sinking, and 2W power dissipation
through the top of the module with an approximate
θ
of 124°C at the junction of the device. The θ
in Tables 3 and 4 can be used to derive the derating
curves for other output voltages.
Safety Considerations
The LTM4602 modules do not provide isolation from V
V
with a rating twice the maximum input current should be
provided to protect each unit from catastrophic failure.
OPTI-LOOP is a registered trademark of Linear Technology Corporation.
R
JC
OUT
SET
SGND
SGND
V
V
between 6°C/W to 9°C/W. This equates to a total
. There is no internal fuse. If required, a slow blow fuse
OUT
OUT
4602 F07
V
12A MAX
OUT
JA
parameters are
JA
JA
for the
values
IN
4602fa
to