General Description

The DS2788 measures voltage, temperature, and cur-

rent, and estimates available capacity for rechargeable

lithium-ion (Li+) and Li+ polymer batteries. Cell charac-

teristics and application parameters used in the calcu-

lations are stored in on-chip EEPROM. The available

capacity registers report a conservative estimate of the

amount of charge that can be removed given the cur-

rent temperature, discharge rate, stored charge, and

application parameters. Capacity estimation is reported

in mAh remaining and percentage of full.

LED display drivers and a debounced input make dis-

play of the capacity information easy. The LED pins can

directly sink current, requiring only a resistor for setting

the current in the LED display, thus reducing space and

cost.

Applications

Power Tools

Electric Bicycles

Electric Vehicles

Uninterruptible Power Supply

Digital Cameras

Features

♦ Five 30mA Open-Drain Drivers for Driving LED

Fuel-Gauge Display

♦ Debounced Fuel-Gauge Display Enable

♦ Internal Voltage Measurement Gain Register for

Trimming External Voltage-Divider

♦ Pin for Driving FETs to Enable Voltage-Divider

Only During Voltage Measurement, Conserving

Power

♦ Precision Voltage, Temperature, and Current

Measurement System

♦ Accurate, Temperature-Stable, Internal Time Base

♦ Absolute and Relative Capacity Estimated from

Coulomb Count, Discharge Rate, Temperature,

and Battery Cell Characteristics

♦ Accurate Warning of Low Battery Conditions

♦ Automatic Backup of Coulomb Count and Age

Estimation to Nonvolatile (NV) EEPROM

♦ Gain and Tempco Calibration Allows the Use of

Low-Cost Sense Resistors

♦ 24-Byte Battery/Application Parameter EEPROM

♦ 16-Byte User EEPROM

♦ 14-Pin TSSOP Package

Stand-Alone Fuel-Gauge IC with

LED Display Drivers

________________________________________________________________

Maxim Integrated Products

1

2

11

PIO

4

12

LED5

3

13

LED4

LED1

14

LED3

1

LED2

TOP VIEW

DS2788

8

VMA

7

DQ

9

SNS

6

10

5

OVD

TSSOP

+

Pin Configuration

Ordering Information

Rev 0; 10/07

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 a lead-free package.

T&R = Tape and reel.

Typical Operating Circuit appears at end of data sheet.

PART

TEMP RANGE

PIN-PACKAGE

DS2788E+

-25°C to +70°C

14 TSSOP

DS2788E+T&R

-25°C to +70°C

14 TSSOP

1-Wire is a registered trademark of Dallas Semiconductor Corp.,

a wholly owned subsidiary of Maxim Integrated Products, Inc.