EV-118

AAT3152 EVAL: High Efficiency 1X/1.5X/2X

Charge Pump For White LED Applications

Introduction

The AAT3152 EVAL board demonstrates the functionality of the AAT3152 and its application as a white LED

backlight driver. The AAT3152 is a low-noise, constant frequency charge pump DC/DC converter with tri-mode

load switch (1X), fractional (1.5X), and doubling (2X) conversion to maximize efficiency and operate over a

wide input voltage range.

The AAT3152 is programmable with the S

driving up to four independent LED channels. Main/sub control is available with eight constant current level

settings from 20mA down to 50µA.

This document describes the evaluation board and its accompanying user interface. In addition, a brief Getting

Started section is included to help the user begin operating the evaluation board. A schematic of the complete

circuit is shown in Figure 1, and the actual board layout is given in Figures 2 and 3. For additional informa-

tion, please consult the AAT3152 product datasheet.

Schematic

Figure 1: Evaluation Board Schematic.

VDD

1

GP5

2

GP4

3

GP3

4

GP2

5

GP1

6

GP0

7

VSS

8

PIC12F675

U2

C3

1

µF

C1

1

µF

C2

1

µF

C4

1

µF

R6

100k

Ω

R1

1k

Ω

R4

330

Ω

R5

330

Ω

C5

10

µF

R2

1k

Ω

R3

1k

Ω

R7

220

Ω

J1

1

2

3

4

5

0

DOWN

SW1

1

2

3

4

5

0

UP

SW2

RED

LED7

1

2

3

4

5

0

CYCLE

SW3

DC+

DC-

D2

D1

D4

D3

GND

DC+

GND

GND

POT 10K

VR4

GRN

LED0

GND

D4

1

EN/SET

2

C1+

3

C1-

4

VOUT

5

C2+

6

C2-

7

VIN

8

GND

9

D1

10

D2

11

D3

12

AAT3152

U1

GND

GND

J2

GND

JP6

DC+

JP5

JPx

EV-118.2005.06.1.0

1