DS2703

`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<sub>PULLUP</sub> as Low as 2.7V
` Max-8 Package (Lead-Free)

Voltage Range on DQ, THM Pins Relative to Ground .....-0.3V to +18V
Voltage Range on VB Pin Relative to Ground ..................-0.3V to +6V
Operating Temperature Range ...............................-40°C to +85°C
Storage Temperature Range .................................-55°C to +125°C
Soldering Temperature See ........IPC/JEDEC J-STD-020A Specification
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only,and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to the absolute maximum rating conditions for extended periods may affect device.

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
just what is required for identifying battery packs manufactured by authorized sources.

The DS2703 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 DS2703 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.