MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER

MPQ2249 Rev.1.01

www.MonolithicPower.com

12

6/11/2014

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PCB Layout

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 and

take figure 5 for reference.

(1) Keep the path of switching current short and

minimize the loop area formed by Input cap,

high-side MOSFET and external switching

diode

(2) Bypass ceramic capacitors are suggested to

be put close to the Vin Pin.

(3) Ensure all feedback connections are short

and direct. Place the feedback resistors and

compensation components as close to the

chip as possible.

(4) Route SW away from sensitive analog areas

such as FB.

(5) Connect IN, SW, and especially GND

respectively to a large copper area to cool

the chip to improve thermal performance

and long-term reliability.

V

IN

V

OUT

GND

Top Layer

Bottom Layer

Figure 2— PCB Layout

Design Specification

The below is a design example following the

application guidelines for the specifications :

Table 2—Design Example Specification

parameter

Symbol

Value

Units

Input Voltage

2.5 — 6

V

Output Voltage

1.8

V

Output Current

3

A

Design Example

The detailed application schematic is shown in

Figure 3. The typical performance and circuit

waveforms have been shown in the Typical

Performance Characteristics section. For more

device applications, please refer to the related

Evaluation Board Datasheets.