Rainbow Electronics DS2788 - Manual

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
♦ Unique ID and Multidrop 1-Wire ® Interface
♦ 14-Pin TSSOP Package
D
S
2
7
8
8
Stand-Alone Fuel-Gauge IC with
LED Display Drivers
________________________________________________________________ Maxim Integrated Products 1
2
11 PIO 4 V DD
12 LED5 3 DV SS
13 LED4 LED1
14 LED3 1 LED2
TOP VIEW
DS2788
8 VMA 7 DQ
9 SNS 6 V SS
10 V IN 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.