Datasheet

VOUT
PH
Vin
TOPSIDE
GROUND
AREA
VIA toGroundPlane
ANALOGGROUND TRACE
EXPOSED
POWERPAD
AREA
COMPENSATION
NETWORK
OUTPUT
INDUCTOR
OUTPUT
FILTER
CAPACITOR
BOOT
CAPACITOR
INPUT
BYPASS
CAPACITOR
INPUT
BULK
FILTER
FREQUENCY SET RESISTOR
SLOWSTART
CAPACITOR
BIASCAPACITOR
AGND
BOOT
VSENSE
COMP
PWRGD
PH
PH
PH
PH
RT
SYNC
SS/ENA
VBIAS
VIN
VIN
VIN
PGND
PGND
PGND
PGND
PH
PH
PH
PGND
PGND
PGND
PGND
PGND
VIN
VIN
PGND
PGND
PGND
PGND
ANALOGGROUND TRACE
Estimated Circuit Area
LAYOUT CONSIDERATIONS FOR THERMAL
TPS54617
SLVS880A – NOVEMBER 2008 – REVISED JANUARY 2009 ........................................................................................................................................... www.ti.com
Figure 11. TPS54617 PCB Layout
The estimated printed circuit board area for the components used in the design of Figure 11 is 0.55 in
2
. This area
does not include test points or connectors.
heat, and any area available must be used when 6 A
or greater operation is desired. Connection from the
exposed area of the PowerPAD to the analog ground
PERFORMANCE
plane layer must be made using 0.013-inch diameter
The RUV package has been chosen to enable a
vias to avoid solder wicking through the vias.
thermal management scheme, allowing a ground
12 vias must be in the PowerPAD area located under
plane to extend beyond both ends of the package.
the device package. Additional vias beyond the
For operation at full rated load current, the analog
twelve recommended may be added in the ground
ground plane must provide an adequate heat
area outside the package footprint to enhance
dissipating area. A 3-inch by 3-inch plane of 1 ounce
thermal performance. The size of the vias outside of
copper is recommended, though not mandatory,
the package, not in the exposed thermal pad area,
depending on ambient temperature and airflow. Most
can be increased to 0.018.
applications have larger areas of internal ground
plane available, and the PowerPAD must be
connected to the largest area available. Additional
areas on the top or bottom layers also help dissipate
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