MP155 – ENERGY EFFICIENT OFF-LINE REGULATOR

MP155 Rev. 1.12

www.MonolithicPower.com

15

10/28/2013

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Layout Guide

PCB layout is very important to achieve reliable

operation,

and

good

EMI

and

thermal

performance. Follow these guidelines to optimize

performance.

1) Minimize the loop area formed by the input

capacitor,

IC

part,

freewheeling

diode,

inductor and output capacitor.

2) Place the power inductor far away from the

input filter.

3) Add a capacitor in the several-hundred pF

range between pin FB and source as close to

the IC as possible.

4) Connect the exposed pad with the Drain pin

to a large copper area to improve thermal

performance.

Top

Bottom Layer

Design Example

Below is a design example following the

application

guidelines

given

the

following

specifications:

Table 4: Design Example

85 to 265Vac

12V

200mA

Figure 11 shows the detailed application

schematic.

The

Typical

Performance

Characteristics section lists typical performance

and

circuit

waveforms.

For

more

device

application, please refer to the related Evaluation

Board Datasheets.