1-Wire SHA-1 Authenticated 1Kb EEPROM with 1.8V Operation

Provides Low-Cost, Secure Bidirectional Authentication Over a Single Contact for Low-Power Applications

Please check latest availability status for a specific part variant.


The DS28E02 combines 1024 bits of EEPROM with challenge-and-response authentication security implemented with the FIPS 180-3 Secure Hash Algorithm (SHA-1). The 1024-bit EEPROM array is configured as four pages of 256 bits with a 64-bit scratchpad to perform write operations. All memory pages can be write protected, and one page can be put in EPROM-emulation mode, where bits can only be changed from a 1 to a 0 state. Each DS28E02 has its own guaranteed unique 64-bit ROM registration number that is factory installed into the chip. The DS28E02 communicates over the single-contact 1-Wire® bus. The communication follows the standard 1-Wire protocol with the registration number acting as the node address in the case of a multidevice 1-Wire network.
DS28E02: Typical Operating Circuit DS28E02: Typical Operating Circuit Enlarge+

Key Features

  • 1024 Bits of EEPROM Memory Partitioned Into Four Pages of 256 Bits
  • On-Chip 512-Bit SHA-1 Engine to Compute 160-Bit Message Authentication Codes (MACs) and to Generate Secrets
  • Write Access Requires Knowledge of the Secret and the Capability of Computing and Transmitting a 160-Bit MAC as Authorization
  • User-Programmable Page Write Protection for Page 0, Page 3, or All Four Pages Together
  • User-Programmable OTP EPROM Emulation Mode for Page 1 ("Write to 0")
  • Communicates to Host with a Single Digital Signal at 12.5kbps or 35.7kbps Using 1-Wire Protocol
  • Switchpoint Hysteresis and Filtering to Optimize Communication Performance in the Presence of Noise
  • Reads and Writes Over 1.75V to 3.65V Voltage Range from -20°C to +85°C
  • 6-Lead TSOC and TDFN Packages


  • Medical Consumable Authentication
  • Printer Cartridge Configuration and Monitoring
  • Reference Design License Management
  • Sensor/Accessory Authentication and Calibration
  • System Intellectual Property Protection

See parametric specs for Secure Authenticators (32)

Part NumberCrypto EngineMemory TypeMemory SizeBus TypeVSUPPLY
Oper. Temp.
DS28E02 SymmetricEEPROM1K x 11-Wire1.75 to 3.65-20 to +85

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

DS9481R-3C7: USB-to-1-Wire/iButton 3.3V Adapter
DS9120: Socket Boards for Evaluating 1-Wire Devices
DS9120P: Socket Boards for Evaluating 1-Wire Devices
DS9120Q: Socket Boards for Evaluating 1-Wire Devices
Product Reliability Reports: DS28E02.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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