Datasheet

LT8582
17
8582f
Figure 8. Suggested Component Placement for Boost and Dual Inductor Inverting Topologies.
Note the Separate Ground Return for the R
T
, SS, and V
C
Components as Well as D2’s Cathode
APPLICATIONS INFORMATION
THERMAL CONSIDERATIONS
Overview
For the LT8582 to deliver its full output power, it is imperative
that a good thermal path be provided to dissipate the heat
generated within the package. This can be accomplished
by taking advantage of the thermal pad on the underside
of the chip. It is recommended that multiple vias in the
printed circuit board be used to conduct heat away from the
chip and into copper planes with as much area as possible.
Power and Thermal Calculations
Power dissipation in the LT8582 chip comes from four
primary sources: switch I
2
R loss, NPN base drive loss
(AC + DC) and chip bias current. The following formulas
assume continuous mode operation, so they should not
be used for calculating thermal losses or efficiency in
discontinuous mode or at light load currents.
1
2
3
4
6
7
9
10
11
12
24
25
23
22
21
19
18
16
15
14
13
L1
s
s
D2
L2
L3
C1
M1
V
IN
+
–
SYNC1
CLKOUT2
C
PWR2
C
PWR1
C
OUT1
C
VIN1
8582 F08
C
VIN2
R
GATE
C
OUT3
D1
GND
V
OUT2
C
OUT2
V
OUT1
17
5
8
20