EV-102

AAT1150 EVAL

1A Buck DC/DC Switch Mode Regulator

Introduction

The AAT1150 MSOP evaluation board demonstrates performance, along with the suggested size and place-

ment of external components, for the AAT1150 integrated buck regulator. The external components are select-

ed for minimum size and optimum operation up to 1A output current. Please refer to the AAT1150 product

datasheet for more details about this product.

Layout

As with all switching power supplies, board layout for the AAT1150 is critical. Special care has been taken with

placement of the external components. The input capacitor (C1) placement is critical and must be located imme-

diately adjacent to the AAT1150. As shown in Figure 2, the LX node trace has been routed under C1 in order

to facilitate placement of C1 close to the IC. The output voltage feedback trace has been routed on the portion

of backside of the board which has a ground plane on the top side (see Figure 3). The trace is routed to avoid

the LX node and associated noise. Please refer to Table 1 for AAT1150 evaluation board specifications.

Figure 1: AAT1150 Evaluation Board Schematic.

Table 1: AAT1150 Evaluation Board Specifications.

Specification

Test Conditions

Min

Typ

Max

Units

Input Voltage

2.7

3.6

5.5

V

Output Error Voltage

±3

%

Output Current

0

1.0

A

4.1µH

L1

C2-C4

3x 22µF

6.3V X5R

10µF

C1

100

R1

0.1µF

C7

100k

R2

GND

FB

1

GND

2

EN

3

4

5

LX

6

LX

7

PGND

8

AAT1150

R3

10kΩ 1%

R4

EN

EV-102.2005.07.1.1

1