L1

U1

GND

V

IN

V

OUT

GND

EN

BP

TPS61253, TPS61254, TPS61256, TPS61258, TPS61259

www.ti.com

SLVSAG8E – SEPTEMBER 2011 – REVISED MARCH 2015

11 Power Supply Recommendations

The power supply can be three-cell alkaline, NiCd or NiMH, or one-cell Li-Ion or Li-Polymer battery. The input

supply should be well regulated with the rating of TPS6125x. If the input supply is located more than a few

inches from the device, additional bulk capacitance may be required in addition to the ceramic bypass capacitors.

An electrolytic or tantalum capacitor with a value of 47 µF is a typical choice.

12 Layout

12.1 Layout Guidelines

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 the ground pins of the IC.

12.2 Layout Example

Figure 43. Suggested Layout (Top)

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Product Folder Links: TPS61253 TPS61254 TPS61256 TPS61258 TPS61259