VIA to Ground Plane
Feedback
Resistors1
Inductor
Output
Capacitor 1
Feedback
Resistors2
Output
Capacitor 2
VOUT
Exposed PAD
FB
GND
PGND
VBA
T
VOUT
SW
NC
PGND
PGND
LBO
SW
VOUT
EN
SYNC
LBI
LBO Resistor
GND
VIA to VBAT Plane
Input
Capacitor
GND
LBI
Resistors1
LBI
Resistors2
TPS61090, TPS61091, TPS61092
www.ti.com
SLVS484C – JUNE 2003 – REVISED DECEMBER 2014
11 Power Supply Recommendations
The device is designed to operate from an input voltage supply range between 1.8 V and 5.5 V. This input supply
must be well regulated. If the input supply is located more than a few inches from the converter, additional bulk
capacitance may be required in addition to the ceramic bypass capacitors. An electrolytic or tantalum capacitor
with a value of 47
μ
F is a typical choice.
12 Layout
12.1 Layout Guidelines
As for all switching power supplies, the layout is an important step in the design, especially at high peak currents
and high switching frequencies. If the layout is not carefully done, the regulator could show stability problems as
well as EMI problems. Therefore, use wide and short traces for the main current path and for the power ground
tracks. The input capacitor, output capacitor, and the inductor should be placed as close as possible to the IC.
Use a common ground node for power ground and a different one for control ground to minimize the effects of
ground noise. Connect these ground nodes at any place close to one of the ground pins of the IC.
The feedback divider should be placed as close as possible to the control ground pin of the IC. To lay out the
control ground, it is recommended to use short traces as well, separated from the power ground traces. This
avoids ground shift problems, which can occur due to superimposition of power ground current and control
ground current.
12.2 Layout Example
Figure 23. Layout Example Schematic
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