General Description

The MAX1772 is a highly-integrated, multichemistry

battery-charger control IC that simplifies the construc-

tion of accurate and efficient chargers. The MAX1772

uses analog inputs to control charge current and volt-

age and can be programmed by the host or hardwired.

High efficiency is achieved by a buck topology with

synchronous rectification.

Maximum current drawn from the AC adapter is pro-

grammable to avoid overloading the AC adapter when

supplying the load and the battery charger simultane-

ously. This enables the user to reduce the cost of the

AC adapter. The MAX1772 provides outputs that can

be used to monitor the current drawn from the AC

adapter, battery-charging current, and the presence of

an AC adapter.

The MAX1772 can charge two to four lithium-ion (Li+)

series cells, easily providing 4A. When charging, the

MAX1772 automatically transitions from regulating cur-

rent to regulating voltage. It is available in a space-sav-

ing 28-pin QSOP package.

Applications

Notebook and Subnotebook Computers

Personal Digital Assistants

Handheld Terminals

Features

o Input Current Limiting

o ±0.5% Output Voltage Accuracy Using Internal

Reference (0°C to +85

°C)

o Programmable Battery Charge Current >4A

o Analog Inputs Control Charge Current and

Charge Voltage

o Monitor Outputs for:

Current Drawn from AC Input Source

Charging Current

AC Adapter Present

o Up to 18.2V (max) Battery Voltage

o 8V to 28V Input Voltage

o > 95% Efficiency

o 99.99% (max) Duty Cycle for Low-Dropout

Operation

o Charges Any Battery Chemistry: Li+, NiCd, NiMH,

Lead Acid, etc.

Low-Cost, Multichemistry Battery-

Charger Building Block

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Maxim Integrated Products

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3

4

5

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9

10

11

12

13

14

IINP

CSSP

CSSN

BST

DHI

LX

VCTL

DLOV

DLO

PGND

CSIP

CSIN

BATT

CELLS

ICTL

REFIN

ACOK

ACIN

ICHG

GND

GND

CCV

CCI

CCS

REF

CLS

LDO

DCIN

QSOP

TOP VIEW

MAX1772

Pin Configuration

19-1772; Rev 4; 2/09

Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

MAX1772EEI

-40

°C to +85°C

28 QSOP

MAX1772EEI+

-40

°C to +85°C

28 QSOP

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.

+

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