EVALUATION

KIT

AVAILABLE

General Description

The MAX8631X/Y charge pump drives up to eight white

LEDs with regulated constant current for uniform inten-

sity. The main group of LEDs (M1–M4) can be driven

up to 30mA per LED for backlighting. The flash group

of LEDs (F1–F4) is independently controlled and can be

driven up to 100mA per LED (or 400mA total). Two

200mA LDOs are on-board to provide power for cam-

era functions. The LDOs’ output voltages are pin-pro-

grammable to meet different camera-module

requirements. By utilizing adaptive 1x/1.5x/2x charge-

pump modes and very-low-dropout current regulators,

the MAX8631X/Y achieves high efficiency over the full

1-cell lithium-battery voltage range. The 1MHz fixed-fre-

quency switching allows for tiny external components,

and the regulation scheme is optimized to ensure low

EMI and low input ripple.

The MAX8631X/Y is available in a 28-pin thin QFN,

4mm x 4mm lead-free package (0.8mm max height).

Applications

Camera Phones and Smartphones

Backlighting and Flash

PDAs, Digital Cameras, and Camcorders

Features

♦ Powers Up to 8 LEDs

Up to 30mA/LED Drive for Backlight

Up to 400mA Total Drive for Flash

♦ Two Internal Low-Noise 200mA LDOs

Battery Discharge

♦ 0.2% Typical LED Current Matching

♦ Adaptive 1x/1.5x/2x Mode Switchover

♦ Flexible Brightness Control

Single-Wire Serial Pulse Interface (32 Steps)

2-Bit Logic (Three Levels)

♦ Low Input Ripple and EMI

♦ 2.7V to 5.5V Supply Voltage Range

♦ Soft-Start, Overvoltage, and Thermal-Shutdown

Protection

♦ 28-Pin Thin QFN, 4mm x 4mm Package

1x/1.5x/2x White LED Charge Pump with

Two LDOs in 4mm x 4mm Thin QFN

________________________________________________________________ Maxim Integrated Products

1

Ordering Information

19-3688; Rev 2; 5/06

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP RANGE

PIN-PACKAGE

MAX8631XETI+

-40°C to +85°C

28 Thin QFN-EP*

4mm x 4mm (T2844-1)

MAX8631YETI+

-40°C to +85°C

28 Thin QFN-EP*

4mm x 4mm (T2844-1)

Pin Configuration appears at end of data sheet.

MAIN ON/OFF

AND DIMMING

MAX8631X/Y

1

µF

10

µF

0.01

µF

10

µF

PIN

IN

PGND

GND

P1

P2

OUT

MAIN

FLASH

OUTPUT

UP TO 480mA

1

µF

1

µF

LDO1

LDO2

C2P

C2N

1

µF

C1P

C1N

REF

SETM

SETF

CAMERA

MODULE

DUAL-LDO

VOLTAGE

SELECTION

INPUT

2.7V TO 5.5V

ENM2

ENM1

ENF

ENLDO

M1

M2

M3

M4

F1

F2

F3

F4

FLASH ON/OFF

DUAL-LDO ON/OFF

Typical Operating Circuit

*EP = Exposed paddle.

+Denotes lead-free package.