1-Cell Stand-Alone Fuel Gauge IC with Li+ Protector and SHA-1 Authentication

Industry's First Complete Fuel Gauge Solution to Integrate a 1-Cell Li+ Protector and SHA-1 Authentication System


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.
DS2784: Typical Operating Circuit DS2784: Typical Operating Circuit Enlarge+

Key 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


  • Cordless VoIP Phones
  • Digital Still and Video Cameras
  • Portable GPS Navigation
  • Smartphones/PDAs
Part Number Functions Battery Type Interface User Data Storage
Parameters Measured Fuel Gauge Algorithm Battery Protection VSUPPLY
Oper. Temp.
min max See Notes
Fuel Gauge
1 Cell Li-Ion 1-Wire 16 EEPROM
Over Voltage
Over/Under Voltage
2.5 4.6 -40 to +85 $3.96 @1k
See All Battery Monitors, Protectors, and Selectors (34)
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.

DS2784EVKIT: Evaluation Kit for the DS2784

Tools & Models

DS2784K Evaluation Kit Software
DS2784K EEPROM Programmer


Related Resources