General Description

The MAX8903A–MAX8903E/MAX8903G/MAX8903H/

MAX8903J/MAX8903Y are integrated 1-cell Li+ charg-

ers and Smart Power Selectors™ with dual (AC adapter

and USB) power inputs. The switch mode charger uses

a high switching frequency to eliminate heat and allow

tiny external components. It can operate with either

separate inputs for USB and AC adapter power, or from

a single input that accepts both. All power switches for

charging and switching the load between battery and

external power are included on-chip. No external

MOSFETs, blocking diodes, or current-sense resistors

are required.

The MAX8903_ features optimized smart power control

to make the best use of limited USB or adapter power.

Battery charge current and SYS output current limit are

independently set. Power not used by the system

charges the battery. Charge current and SYS output cur-

rent limit can be set up to 2A while USB input current can

be set to 100mA or 500mA. Automatic input selection

switches the system from battery to external power. The

DC input operates from 4.15V to 16V with up to 20V pro-

tection, while the USB input has a range of 4.1V to 6.3V

with up to 8V protection.

The MAX8903_ internally blocks current from the bat-

tery and system back to the DC and USB inputs when

no input supply is present. Other features include pre-

qual charging and timer, fast charge timer, overvoltage

protection, charge status and fault outputs, power-OK

monitors, and a battery thermistor monitor. In addition,

on-chip thermal limiting reduces battery charge rate

and AC adapter current to prevent charger overheat-

ing. The MAX8903_ is available in a 4mm x 4mm, 28-pin

thin QFN package.

The various versions of the MAX8903_ allow for design

flexibility to choose key parameters such as system

regulation voltage, battery prequalification threshold,

and battery regulation voltage. The MAX8903B/

MAX8903E/MAX8903G also includes power-enable on

battery detection. See the

Selector Guide section for

complete details.

Applications

Features

o Efficient DC-DC Converter Eliminates Heat

o 4MHz Switching for Tiny External Components

o Instant On—Works with No/Low Battery

o Dual Current-Limiting Inputs—AC Adapter or USB

Automatic Adapter/USB/Battery Switchover to

Support Load Transients

50m

Ω System-to-Battery Switch

Supports USB Spec

o Thermistor Monitor

o Integrated Current-Sense Resistor

o No External MOSFETs or Diodes

o 4.1V to 16V Input Operating Voltage Range

2A 1-Cell Li+ DC-DC Chargers for USB

and Adapter Power

________________________________________________________________

Maxim Integrated Products

1

19-4410; Rev 4; 5/11

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

EVALUATION

KIT

AVAILABLE

Pin Configuration appears at end of data sheet.

Selector Guide appears at end of data sheet.

CHARGE

AND

SYS LOAD

SWITCH

DC

SYS

BAT

AC

ADAPTER

OR USB

SYSTEM

LOAD

BATTERY

GND

USB

USB

CHARGE

CURRENT

LOAD

CURRENT

LX

CS

PWM

STEP-DOWN

MAX8903_

Typical Operating Circuit

Smart Power Selector is a trademark of Maxim Integrated

Products, Inc.

PDAs, Palmtops, and

Wireless Handhelds

Personal Navigation

Devices

Smart Cell Phones

Portable Multimedia

Players

Mobile Internet Devices

Ultra Mobile PCs

Ordering Information

+

Denotes a lead(Pb)-free/RoHS-compliant package.

*

EP = Exposed pad.

**

Future product—contact factory for availability.

T = Tape and reel.

PART

TEMP RANGE

PIN-PACKAGE

MAX8903AETI+T

-40°C to +85°C

28 Thin QFN-EP*

MAX8903BETI+T

-40°C to +85°C

28 Thin QFN-EP*

MAX8903CETI+T

-40°C to +85°C

28 Thin QFN-EP*

MAX8903DETI+T

-40°C to +85°C

28 Thin QFN-EP*

MAX8903EETI+T

-40°C to +85°C

28 Thin QFN-EP*

MAX8903GETI+T

-40°C to +85°C

28 Thin QFN-EP*

MAX8903HETI+T

-40°C to +85°C

28 Thin QFN-EP*

MAX8903JETI+T**

-40°C to +85°C

28 Thin QFN-EP*

MAX8903YETI+T

-40°C to +85°C

28 Thin QFN-EP*