LTM8026 LINER [Linear Technology], LTM8026 Datasheet - Page 19

• Manufacturer Part Number: LTM8026
• Description: 36VIN, 5A, 2-Quadrant CVCC Step-Down
• Manufacturer: LINER [Linear Technology]

applicaTions inForMaTion
No Output Current Sharing
The LTM8052 is a two quadrant device, able to both sink
and source current to maintain voltage regulation. It is
therefore not suitable for current sharing.
PCB Layout
Most of the headaches associated with PCB layout have
been alleviated or even eliminated by the high level of
integration of the LTM8052. The LTM8052 is neverthe-
less a switching power supply, and care must be taken to
minimize EMI and ensure proper operation. Even with the
high level of integration, you may fail to achieve specified
operation with a haphazard or poor layout. See Figure 6
for a suggested layout. Ensure that the grounding and
2. Place the C
heat sinking are acceptable.
A few rules to keep in mind are:
1. Place the R
their respective pins.
and GND connection of the LTM8052.
ADJ
IN
capacitor as close as possible to the V
and R
T
resistors as close as possible to
Figure 6. Layout Showing Suggested External Components,
GND Plane and Thermal Vias.
GND
•
THERMAL AND INTERCONNECT VIAS
C
OUT
V
OUT
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•
•
V
OUT
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•
IN
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•
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•
•
•
•
•
•
GND
3. Place the C
4. Place the C
5. Connect all of the GND connections to as large a copper
6. Use vias to connect the GND copper area to the board’s
•
•
GND
•
•
•
•
V
ground currents flow directly adjacent or underneath
the LTM8052.
pour or plane area as possible on the top layer. Avoid
breaking the ground connection between the external
components and the LTM8052.
internal ground planes. Liberally distribute these GND
vias to provide both a good ground connection and
thermal path to the internal planes of the printed circuit
board. Pay attention to the location and density of the
thermal vias in Figure 6. The LTM8052 can benefit from
the heat sinking afforded by vias that connect to internal
GND planes at these locations, due to their proximity
to internal power handling components. The optimum
number of thermal vias depends upon the printed
circuit board design. For example, a board might use
very small via holes. It should employ more thermal
vias than a board that uses larger holes.
•
•
OUT
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•
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•
C
IN
and GND connection of the LTM8052.
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•
•
•
•
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V
V
IN
IN
OUT
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•
•
8052 F06
IN
and C
capacitor as close as possible to the
SYNC
RUN
OUT
capacitors such that their
LTM8052
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8052fa