MP2611 – 2A, 1-CELL SWITCHING CHARGER FOR USB AND ADAPTER POWER

MP2611 Rev. 1.12

www.MonolithicPower.com

18

12/7/2012

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PCB Layout Guide

PCB layout is important to meet specified noise,

efficiency

and

stability

requirements.

The

following design considerations can improve

circuit performance:

1) Route the power stage adjacent to their

grounds. Aim to minimize the high-side

switching node (SW, inductor), trace lengths

in the high-current paths and the current-

sense resistor trace. Keep the switching

node short and away from the feedback

network.

2) The exposed thermal pad on the backside of

the MP2611 package must be soldered to

the PGND plane. There must be sufficient

thermal vias underneath the IC connected to

the ground plane on the other layers.

3) Connect the charge current sense resistor to

CSP (pin 9), BATT (pin 8) with a Kelvin

contact. Minimize the length and area of this

circuit loop.

4) Place the input capacitor as close as

possible to the ACIN/USBIN and PGND pins.

Place the output inductor close to the IC as

and connect the output capacitor between

the inductor and PGND of the IC. This

minimizes the current path loop area from

the SW pin through the LC filter and back to

the PGND pin.

5) Connect AGND and PGND at a single point.