General Description

The MAX1660 digitally controlled fuel-gauge interface

executes two essential functions for rechargeable bat-

tery-pack management: fuel gauging and pack overcur-

rent protection. It accurately monitors a battery pack’s

charge and discharge current flow, and records each

using two independent, on-board Coulomb counters.

Each counter’s contents are externally accessible via a

System Management Bus (SMBus™)-compatible 2-wire

serial interface. An optional third wire interrupts the

microcontroller (µC) when the charge or discharge

counters reach a preset value, or when an overcurrent

condition (charge or discharge) occurs. In the event of

an overcurrent or short-circuit condition, the MAX1660

disconnects the load and alerts its host. The MAX1660’s

flexibility allows accurate fuel gauging for any battery

chemistry, using any desired control algorithm.

The MAX1660 operates with battery voltages from +4V

to +28V and provides two micropower shutdown

modes, increasing battery lifetime. To minimize total

parts count, the device integrates a precision 2.00V

system-reference output, a 3.3V linear-regulator output

that can supply up to 5mA to power external circuitry,

and a power-on reset output for the system µC. The

MAX1660 is available in a 16-pin QSOP package.

________________________Applications

Smart-Battery Packs

Battery-Pack Fuel Gauging

Battery-Pack Overcurrent

Digital Current-Sense

Protection

Instrumentation

Industrial-Control System

Analog-to-Digital

Interfaces

Conversion

____________________________Features

o 1% Accuracy over a 600µA to 4A Current Range

Ω)

o 5µV Input Offset Voltage (28µV max)

o SMBus 2-Wire (plus optional interrupt)

Serial Interface

o 2.00V Precision System Reference Output

o 3.3V Linear-Regulator Output Powers External

Circuitry

o Two Micropower Shutdown Modes

o Independent 32-Bit Charge and Discharge

Coulomb Counters

o Battery-Overcharge/Overdischarge Protection

o Battery Short-Circuit/Overcurrent Protection

o On-Board Power MOSFET Drivers

o 80µA Quiescent Current

o <1µA Shutdown Current

o Small 16-Pin QSOP Package

(same board area as 8-pin SO)

Digitally Controlled

Fuel-Gauge Interface

________________________________________________________________

Maxim Integrated Products

1

19-1308; Rev 1; 10/98

EVALUATION

KIT MANUAL

FOLLOWS

DATA

SHEET

SMBus is a trademark of Intel Corp.

*

Patent pending

MAX1660

BATT

CS

AGND

REF

OCI

ODI

GND

SCL

SDA

SHDN

OCO

VL

GND

PACK-

PACK+

µC

RST

INT

ODO

___________________________________________________Typical Operating Circuit

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.

PART

MAX1660EEE

-40°C to +85°C

TEMP. RANGE

PIN-PACKAGE

16 QSOP

Ordering Information

Pin Configuration appears at end of data sheet.