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Low-Cost I²C Battery Monitor

Low-cost battery fuel gauge that monitors current, voltage, and temperature

Product Details

Key Features

Parametric specs for Battery Fuel Gauges, Protectors, and Monitors
Functions Fuel Gauge
Battery Type 1 Cell Li-Ion
3-Cell NiMH
Interface 2-Wire
Parameters Measured Current
Temperature
Voltage
End Equipment Host
VSUPPLY (V) (min) 2.5
VSUPPLY (V) (max) 5.5
Package/Pins UMAX/8
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
2.65
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Simplified Block Diagram

Technical Docs

Data Sheet Low-Cost I²C Battery Monitor Jun 22, 2009

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Parameters

Parametric specs for Battery Fuel Gauges, Protectors, and Monitors
Functions Fuel Gauge
Battery Type 1 Cell Li-Ion
3-Cell NiMH
Interface 2-Wire
Parameters Measured Current
Temperature
Voltage
End Equipment Host
VSUPPLY (V) (min) 2.5
VSUPPLY (V) (max) 5.5
Package/Pins UMAX/8
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
2.65

Key Features

  • 16-Bit Bidirectional Current Measurement
    • 1.56µV LSB, ±51.2mV Dynamic Range
    • 104µA LSB, ±3.4A Dynamic Range (RSNS = 15mΩ)
  • Current Accumulation Register Resolution
    • 6.25µVhr LSB, ±204.8mVh Range
    • 0.417mAhr LSB, ±13.65Ah Range (RSNS = 15mΩ)
  • 11-Bit Voltage Measurement
  • 4.88mV LSB, 0V to 5V Input Range
  • 11-Bit Temperature Measurement
  • 0.125°C Resolution, -20°C to +70°C
  • Industry Standard I²C Interface
  • Low Power Consumption:
    • Active Current: 70µA typical, 100µA max
    • Sleep Current: 1µA typical, 3µA max

Applications/Uses

  • Cellular
  • GPS
  • Handheld Products
  • PDAs

Description

The DS2745 remains in production, however, for new projects, we recommend ModelGauge m5 MAX17055 fuel gauge.

The DS2745 provides current-flow, voltage, and temperature measurement data to support battery-capacity monitoring in cost-sensitive applications. The DS2745 can be mounted on either the host side or pack side of the application. Current measurement and coulomb counting is accomplished by monitoring the voltage drop across an external sense resistor, voltage measurement is accomplished through a separate voltage-sense input, and temperature measurement takes place on-chip. A standard I²C interface with software programmable address gives the controlling microprocessor access to all data and status registers inside the DS2745. A low-power sleep mode state conserves energy when the cell pack is in storage.

Simplified Block Diagram

DS2745 provides current-flow, voltage, and temperature measurement data to support battery-capacity monitoring in cost-sensitive applications | Block Diagram DS2745 provides current-flow, voltage, and temperature measurement data to support battery-capacity monitoring in cost-sensitive applications | Block Diagram Zoom icon

Technical Docs

Data Sheet Low-Cost I²C Battery Monitor Jun 22, 2009

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .