DS2784

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


Description

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

Applications/Uses

  • Cordless VoIP Phones
  • Digital Still and Video Cameras
  • Portable GPS Navigation
  • Smartphones/PDAs
Part Number Functions Battery Type Interface User Data Storage
(Bytes)
Parameters Measured Fuel Gauge Algorithm Battery Protection VSUPPLY
(V)
VSUPPLY
(V)
Features Oper. Temp.
(°C)
Budgetary
Price
min max See Notes
DS2784 
Fuel Gauge
Protector
1 Cell Li-Ion 1-Wire 16 EEPROM
Current
Temperature
Time
Voltage
FuelPack
Over Voltage
Over-Current
Over-Temperature
Over/Under Voltage
2.5 4.6
Digital Current Accumulation
Internal MOSFET Drivers
On-chip Remaining Capacity Algorithms
Protection Circuitry
SHA-1 Authentication
Unique ID
-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

Software
DS2784K Evaluation Kit Software
DS2784K EEPROM Programmer

 

Related Resources


MAX14676, MAX14676A
Wearable Charge Management Solution

  • Extend System Use Time Between Battery Charging
  • Easy-to-Implement Li+ Battery Charging
  • Minimize Power-Management Footprint though High Integration

MAX14676, MAX14676A
Wearable Charge Management Solution

  • Extend System Use Time Between Battery Charging
  • Easy-to-Implement Li+ Battery Charging
  • Minimize Power-Management Footprint though High Integration