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REV: 071805
Note:
Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here:
www.maxim-ic.com/errata
.
GENERAL DESCRIPTION
The DS2703 provides a robust cryptographic solution
to ensure the authenticity of Li-Ion battery packs for
cell phone, PDA, and portable computing devices.
The DS2703 employs the Secure Hash Algorithm
(SHA-1) specified in the Federal Information
publication 180-1 and 180-2, and ISO/IEC 10118-3.
SHA-1 is designed for authentication
required for identifying battery packs manufactured
by authorized sources.
The device’s SHA-1 engine processes a host
transmitted challenge using its stored 64-bit secret
key and unique 64-bit ROM ID to produce a 160-bit
response word for transmission back to the host. The
secret key is securely stored on-chip and never
transmitted between the battery and the host. A
DS2703-based system produces a high degree of
authentication security between a host system and its
removable battery or other peripheral devices.
The Thermistor Multiplexer feature allows a three
contact battery pack configuration to support data
and thermistor functions. When activated through
1-Wire command, the THM pin presents the
thermistor impedance on the data contact and
disconnects internal loading from the node.
TYPICAL OPERATING CIRCUIT
just what is
DS2703
VSS
DQ
DATA
PACK +
PACK -
VB
150
Li-Ion
Protection
THM
BATTERY PACK
0.22 F
FEATURES
Secure Challenge and Response Authentication
Using the SHA-1 Algorithm
Directly Powered by the Dallas 1-Wire
Interface
with 16kpbs Standard and 143kpbs Overdrive
Communication Modes
Unique 64-Bit Serial Number
Thermistor Multiplexer
Operates with V
PULLUP
as Low as 2.7V
Max-8 Package (Lead-Free)
ORDERING INFORMATION
PART
TEMP RANGE
DS2703U
-20 C to +70 C
PIN-PACKAGE
Max-8
DS2703U on
Tape-and-Reel
Max-8
DS2703U+ on
Tape-and-Reel
DS2703U/T&R
-20 C to +70 C
DS2703U+
-20 C to +70 C
DS2703U+T&R
-20 C to +70 C
+ Denotes lead-free package.
APPLICATIONS
2.5G/3G Wireless Handsets
PDAs
Handheld or Notebook Computers and Terminals
Digital Still and Video Cameras
PIN CONFIGURATION
VSS
DQ
3
DS2703
SHA-1 Battery Pack
Authentication IC
www.maxim-ic.com
TOP VIEW
MAX
DS2703U+
NC
NC
NC
NC
VB
THM
6
8
7
5
1
2
4
1-Wire is a registered trademark of Dallas Semiconductor.