MP38115 – 4A, 5.5V SYNCHRONOUS STEP-DOWN SWITCHING REGULATOR

MP38115 Rev. 0.92

www.MonolithicPower.com

7

8/11/2009

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Table 2—Suggested Surface Mount Inductors

Manufacturer

Part

Number

Inductance

(μH)

Max DCR

(mΩ)

Current Rating

(A)

Dimensions

L x W x H (mm3)

Wurth Electronics

744310055

0.55

4.5

14

7×6.9×3

744310095

0.95

7.4

11

7×6.9×3

TOKO

B1015AS-1R0N

1

11

6.9

8.4×8.3×4

PCB Layout Guide

PCB layout is very important to achieve stable

operation. It is highly recommended to duplicate

EVB layout for optimum performance. If change

is necessary, please follow these guidelines as

follows. Here, the typical application circuit is

taken as an example to illustrate the key layout

rules should be followed.

1) For MP38115, a PCB layout with more than

(or) four layers is recommended.

2) The high current paths (GND, IN and SW)

should be placed very close to the device with

short, direct and wide traces.

3) For MP38115, two input ceramic capacitors (2

x (10μF~22μF)) are strongly recommended to be

placed on both sides of the MP38115 package

and keep them as close as possible to the “IN”

and “GND” pins.

4) An RC low pass filter is recommended for

VCC supply. The VCC decoupling capacitor must

be placed as close as possible to “VCC” pin and

“GND” pin.

5) The external feedback resistors shall be

placed next to the FB pin. Keep the FB trace as

short as possible. Don’t place test points on FB

trace if possible.

6) Keep the switching node SW short and away

from the feedback network.

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