DS2740

High-Precision Coulomb Counter

High-Precision Battery Fuel Gauge Costs Less than $1.00 Ideal for Handheld Products


Description

The DS2740 provides high-precision current-flow measurement data to support battery-capacity monitoring in cost-sensitive applications. Current is measured bidirectionally over a dynamic range of 15 bits (DS2740U) or 13 bits (DS2740BU), with the net flow accumulated in a separate 16-bit register. Through its 1-Wire® interface, the DS2740 allows the host system read/write access to status and current measurement registers. Each device has a unique factory-programmed 64-bit net address that allows it to be individually addressed by the host system, supporting multibattery slot operation. The interface can be operated with standard or overdrive timing.

Although the DS2740 is primarily intended for location on the host system, it is also suited for mounting in the battery pack. The DS2740 and FuelPack™ algorithms, along with host measurements of temperature and voltage, form a complete and accurate solution for estimating remaining capacity.

Key Features

  • 15-Bit Bidirectional Current Measurement (DS2740U)
    • 1.56µV LSB and ±51.2mV Dynamic Range
    • 78µA LSB and ±2.56A Dynamic Range with External 20mΩ Sense Resistor (RSNS)
    • 156µA LSB and ±5.12A Dynamic Range with External 10mΩ Sense Resistor (RSNS)
  • 13-Bit Bidirectional Current Measurement (DS2740BU)
    • 6.25µV LSB and ±51.2mV Dynamic Range
    • 312µA LSB and ±2.56A Dynamic Range with External 20mΩ Sense Resistor (RSNS)
    • 625µA LSB and ±5.12A Dynamic Range with External 10mΩ Sense Resistor (RSNS)
  • Analog Input Filter (IS1, IS2) Extends Dynamic Range for Pulse-Load Applications
  • Current Accumulation Register Resolution
    • 6.25µVhr (Both DS2740U and DS2740BU)
    • 0.3125mAhr with External 20mΩ RSNS
    • 0.6250mAhr with External 10mΩ RSNS
  • Dallas 1-Wire Interface
    • Unique 64-Bit Device Address
    • Standard and Overdrive Timings (OVD)
  • Low Power Consumption:
    • Active Current: 65µA max
    • Sleep Current: 1µA max

Applications/Uses

  • Cell Phones
  • Digital Still Cameras
  • Portable Entertainment Devices
  • Smart Battery Packs/Chargers
Part Number Functions Battery Type Interface Parameters Measured Applications VSUPPLY
(V)
VSUPPLY
(V)
Package/Pins Oper. Temp.
(°C)
Budgetary
Price
min max See Notes
DS2740  Fuel Gauge
1 Cell Li-Ion
3-Cell NiMH
1-Wire Current Pack 2.7 5.5
µMAX/8
-40 to +85 $1.79 @1k
See All Battery Monitors, Protectors, and Selectors (38)
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.

Tools & Models

Software
DS2740K Evaluation Kit Software

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