• Provides Authentication of Battery Packs Through SHA-1 Engine Based HMAC
• 160 Bytes OTP, 16 Bytes EEPROM
• Internal Time-Base Eliminates External Crystal Oscillator
• Low Power Operating Modes:
  • Active: < 50 µA
  • Sleep: 8 µA Typical
• Single-Wire SDQ Interface
• Powers Directly From the Communication Bus
• 6 Lead SON Package
• APPLICATIONS
  • Cellular Phones
  • PDA and Smart Phones
  • MP3 Players
  • Digital Cameras
  • Internet Appliances
  • Handheld Devices

The bq26100 provides a method to authenticate battery packs, ensuring that only packs manufactured by authorized sub-contractors are used in the end application. The security is achieved using the SHA-1 hash function inside the widely adopted HMAC construction. A unique 128-bit key is stored in each bq26100 device, allowing the host to authenticate each pack.

The bq26100 communicates to the system over a simple one-wire bi-directional serial interface. The 5-kbits/s SDQ bus interface reduces communications overhead in the external microcontroller. The bq26100 also derives power over the SDQ bus line via an external capacitor.