DS2784_10 Datasheet, PDF (1/43 Pages) Maxim Integrated Products – 1-Cell Stand-Alone Fuel Gauge IC with Li+ Protector and SHA-1

19-4636; 4/10
www.maxim-ic.com
DS2784
1-Cell Stand-Alone Fuel Gauge IC with
Li+ Protector and SHA-1
GENERAL DESCRIPTION
The DS2784 operates from 2.5V to 4.6V for integration
in battery packs using a single lithium-ion (Li+) or Li+
polymer cell. Available capacity is reported in mAh and
as a percentage. Safe operation is ensured with the
included Li+ protection function and SHA-1-based
challenge-response authentication.
Precision measurements of voltage, temperature, and
current, along with cell characteristics and application
parameters are used to estimate capacity. The
available capacity registers report a conservative
estimate of the amount of charge that can be removed
given the current temperature and discharge rate.
In addition to the nonvolatile (NV) storage for cell
compensation and application parameters, 16 bytes of
EEPROM memory is made available for the exclusive
use of the host system and/or pack manufacturer. This
facilitates battery lot and date tracking or NV storage of
system or battery usage statistics.
A 1-Wire^® interface provides serial communication at
16kbps or 143kbps to access data registers, control
registers, and user memory. Additionally, 1-Wire
communication enables challenge-response pack
authentication using SHA-1 as the hash algorithm in a
hash-based message authentication code (HMAC)
authentication protocol.
FEATURES
 Precision Voltage, Temperature, and Current
Measurement System
 Available Capacity Estimated from Coulomb
Count, Discharge Rate, Temperature, and Cell
Characteristics
 Estimates Cell Aging Using Learn Cycles
 Uses Low-Cost Sense Resistor
 Allows for Calibration of Gain and
Temperature Coefficient
 Li+ Safety Circuitry—Overvoltage,
Undervoltage, Overcurrent, Short-Circuit
Protection
 Programmable Safety Thresholds for
Overvoltage and Overcurrent
 Authentication Using SHA-1 Algorithm and
64-Bit Secret
 32-Byte Parameter EEPROM
 16-Byte User EEPROM
 Dallas 1-Wire Interface with 64-Bit Unique ID
 Tiny, Pb-Free, 14-Pin TDFN Package Embeds
Easily in Battery Packs Using Thin Prismatic
Cells
APPLICATIONS
Smartphones/PDAs
Digital Still and Video Cameras
Cordless VoIP Phones
Portable GPS Navigation
PIN CONFIGURATION
Modes and commands are capitalized for clarity.
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
ORDERING INFORMATION
PART
TEMP RANGE
DS2784G+
-40°C to +85°C
DS2784G+T&R
-40°C to +85°C
+Denotes a lead(Pb)-free/RoHS-compliant package.
T&R = Tape and reel.
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TOP MARK
D2784
D2784
PIN PACKAGE
14 TDFN (3mm x 5mm)
14 TDFN (3mm x 5mm)